MCAT PRACTICE QUESTIONS
why do proteins fold spontaneously?
to reach the lowest energy level
treatment can happen with a
vector
sigmoidal curve is always indicative of ______
cooperativity
emotional
emotion
Ksp
solubility product [x-][y-]
Ions
Oxyanion: Dissolves in water & produces acidic soln Base: Dissolves ONLY in acidic soln
IP = Ksp means
equilibrium (saturated), if its higher its supersaturated
what is the function of the scrotum?
keep the testes at the best temperature for sperm production
What is the order of the electromagnetic spectrum from lowest frequency to highest frequency?
"rattlesnakes may inject venom under Xtreme aGitation" radio waves, microwaves, infrared, visible, ultraviolet, x-ray, gamma.
non-competitive inhibitor? how are Km and Vmax affected?
- A substance that reduces the activity of an enzyme by binding to an allosteric site, -Vmax decreases, Km not altered
Denaturation
-↑ in temp --> Secondary & tertiary breakdown -loss of function & coil
which end does telomerase add nucleotides to?
3' aka the end!!
Purines
A and G
Hind 3 sequence
AAGCTT
Mixed methods research
Both quantitative and qualitative
current equation
I = Q/t aka current = charge over time units: C/sec
Dissociation
If it's highly negative --> It will show the LEAST dissociation
D amino acids can't be substituted for
L amino acids with the same enzyme
First organ that blood from the small intestine enters
Liver
Where is ACE made
Lungs
When glycerol reacts with 3 different FAs, how many stereocenters are generated
Only 1 at C2
What intron region contains sequences that influence splicing
Promoter
Meiosis
Prophase I Metaphase I Anaphase I: nondisjunction (failure of homolog chromosomes to separate Telophase I
Ether
R-O-R
antisense drugs prevent
TRANSLATION Not transcription
deprotonated or protonated? pKa > pH = pH > pKa =
protonated, deprotonated
Why do diabetic patients' brains still receive adequate glucose
The brain uses insulin-independent glucose uptake mechanisms
If one measure shows a significant effect and another one doesn't, what measure do you go with?
The one that doesn't
Power=
Work/time
Cultural and Biosocial Development (Vygotsky)
Zone of proximal development (learning skills)
Rate of diffusion is directly related to:
[ ] gradient, KE, & temp
addition reaction
a chemical reaction in which two or more substances combine to form a new compound
cross-sequential design
a combination of the longitudinal and cross-sectional designs
Totiopotency
ability of a cell to develop into any matter cell type
place theory
able to hear diff pitches because diff sound waves trigger activity at diff parts of cochlear membrane
Main purpose of small intestine
absorption of nutrients
Ketone bodies are converted into:
acetyl-coA
Will an acidic salt be more soluble in acid or base?
base
Hemorrhage =
bleeding
Lining of mouth
ectoderm
oocyte
egg cell
dichotic listening
hear different messages in each ear
you got this
hell yeah
What type of information requires conscious effort?
novel info
Where would you expect to see radioactively labelled uracil incorporated
ribosome
R is
right (clockwise)
What is enthalpy?
the heat content of a system
Power
W/T or mgh/T
which tissue is likely to not have very many protons (detected by MRI) Kidney eyes femur biceps
femur
Molecular orbitals
-Bonding: favorable, overlap of same sign, ↓ energy -Antibonding: unfavorable, overlap opp sign, ↑ energy
Genes
-Codominance: multiple alleles of same gene expressed -Variable expressivity: diff manifestation from same genotype
Adaptive radiation
one species in many environments --> multiple species
how does testosterone actually affect transcription/translation?
"diffuses" inside the cell, binds to a carrier protein in THE CYTOPLASM, then goes inside the nucleus and affects transcription and translation
Isoforms
-diff isoforms are expressed from single genes through alternative splicing of exons of primary transcript
Acetone
-pair of tautomers, ketone, carbonyl bond is stronger than C=C bond, ↓ BP, polar aprotic (no H bonds)
How many H bond donors and acceptors does G have?
2 donors, 1 acceptor
log of 1000 is
3
1 mol = ___ atoms
6.02x10^23
Proton-NMR
-Sp3 (0-3), Sp2 (4-6), Sp (2-3) -Aldehyde (9-10), Carbox acid (10.5-12), Aromatic (6-8.5)
A car travels 90 meters due north in 15 seconds. Then the car turns around and travels 40 meters due south in 5.0 seconds. What is the magnitude of the average velocity of the car during this 20-second interval? A. 2.5 m/s B. 5.0 m/s C. 6.5 m/s D. 7.0 m/s
A. The basic equation is v = d/t. The DISPLACEMENT of the car is 90 m - 40 m = 50 m, the total time is 20s. V = 50m/20s.
stereochemistry
Epimer: differ at single carbon (anomeric = alpha/beta) Anomer: differ in arrangement at C-1 carbon
Density of an object is proportionality to weights in air and water
Wair/(Wair - Ww)
When is glucagon released?
When blood glucose levels are low or "in a starved state" ===> stimulates beta oxidation
maniac depressive disorder
aka bipolar alternating mania and depression
diamagnetic
all the electrons are paired not attracted to external magnetic field (weakly repelled)
hemoglobin is
allosteric
What is beta oxidation?
breaking fatty acids down directly to acetyl coA to be used in the citric acid cycle
portal vein
brings blood to the liver from the intestines .˙. (nutrient rich blood)
After consuming lots of salt, would you expect to have an increase or decrease in aldosterone levels
decrease b/c aldosterone increases salt reabsorption
explosions happen when
delta G < 0
confirmation bias
a tendency to search for information that supports our preconceptions and to ignore or distort contradictory evidence
product energy higher than reactancts
endothermic
Loop of henle
exchange w/ vasa recta & adjusts solute amount in urine
T/F skin is involved in respiration
false!
Substance category with lowest risk of dependance
hallucinogens
content validity
rationale for each test item
antibodies are specific to a
single antigen
resting membrane potential is maintained by what channels
ungated channels
selection bias
when groups are formed in a non-random fashion
density of water
1 g/mL (or 1 g/cm³) or 1000 kg/m^3
Menstruation vs Ovulation
Menstruation: ↓ FSH/LH Ovulation: ↑ LH
signal sequence
directs protein to particular organelle (transmembrane)
explain tyrosine derived hormones
- can act as either proteins or steroids
Power(circut)=
(I^2) R I is current R is resistance
Electrostatic force =
(Kq1q2)/(r^2)
isothermal
(no temp change) delta T= 0 then delta E=zero
Cell-cell junctions
-Gap: intercellular transport, form discont branch -Tight: ↓ paracellular transport, form bands
Respiratory cilia
-move mucus in lung & upper resp tract --> pharynx for disposal by swallowing -protect against infection by removing bacteria/virus -responsible for cough reflex -not in alveoli
when Q is 0 = ______ when Q is infinity = _____
0 = we have all reactants infinity = all products
Wspring
0.5 kx^2
a total potential difference around any closed loop of a circuit is
0V
important enzymes in the duodenum that helps DIGEST (breaks down)
1- protein digestion: brush border PEPTIDASE + pancreas enzymes trypsin + chymotrypsin 2- carb digestion: brush border LACTASE + pancreas AMYLASE 3- nucleotides: brush border NUCLEOSIDASES 4- fats: BILE from liver & gallbladder + LIPASE from pancreas
IR tips Carbonyl is at ____ OH group looks like a
1700 big swoop down above 3000
How much work is done by a 20 N force pushing a 50 kg block 10 m?
200 J, EVEN THOUGH IT IS PUSHINGA 50 KG BLOCK ALL THAT MATTERS IS THE FORCE APPLIED AND THE DISTANCE TRAVELED
the following reaction occurs spontaneously Cd
2H+ --> Cd2+ + H2 Which of the following has the highest electron affinity? A. Cd B. H+ C. Cd2+ D. H2 + H+ the reaction equation shows the reduction of H+ by Cd. Because H+ accepts the electron readily from Cd, it can be determined that H+ has the highest electron affinity
endoderm develops
epithelial linings of digestive and resp tract liver pancreas thyroid bladder
triaglycerol holds ___ times as much energy than glycogen
6 times so to get the same amount of energy it would take 6 times the weight of glycogen
How many rounds of beta oxidation are needed with an 18 carbon molecule
9 - 1 = 8
what is the pKa of an amine group and COOH respectively?
9, 2
chemical shift equation
= [(observed shift from TMS in Hz)(10^6)]/spectrometer frequency in Hz
G protein
A GTP-binding protein that relays signals from a plasma membrane signal receptor, known as a G protein-coupled receptor, to other signal transduction proteins inside the cell.
spurious relationship/correlation
A spurious correlation is a relationship between two variables that appear to have association with each other but actually do not.
Zwitterions
ASP, GLUT, TRYP
start codon
AUG
Blood pathway to kidneys
Aorta -> renal artery -> Afferent arterioles --> Glomerulus --> Efferent arterioles --> Vasa recta --> renal veins
Interpersonal attraction
Appearance, Similarity, Proximity, Self-disclosure, Reciprocity
In which of the following does sound travel most rapidly? A. Air ( 0°C B. water (10°C) C. Iron (20°C) D. Sound travels at approximately the same speed in all of the above
C. The speed of sound is greatest by far in a solid because of the strong intermolecular bonds and close proximity of the molecules leads to a stiff medium in which to propagate
Telomerase sequence
CCCAAUCCC *Note: this is a reverse transcriptase, cis-acting sequence
what hormone stimulates the gallbladder to release bile?
CCK
What circuit elements store energy
Capacitors Batteries
Why is blood flow greater in capillaries than arteries?
Capillaries have the greatest cross sectional area of any blood vessel type
Cartilage vs joints
Cartilage: firm, elastic, avascular, non-innervated Joints: immoveable (fused, fibrous, sutured) vs moveable (ligament, synovial capsule)
Atomic radius
Cations have a smaller radius then neutral form & Anions have a larger radius than neutral form
Demographic Transition Model
Drop in death rate --> Drop in birth rate --> population stabilized
Menstrual cycle
Follic(egg develops), Ovulation (egg releases), Luteal (prog peaks), Menses (shedding)
Nephron pathway
Glomerulus --> bowmans capsule --> PCT --> loop of henle --> DCT --> collecting duct
List all strong acids
HCl, HBr, HI, H2SO4, HNO3, HClO4
strong acids
HI HBr HClO4 HCl HClO3 H2SO4 HNO3
What is the cause of color change when something is cooked?
Heat disrupts intermolecular attractions & denatures protein that separates it from pigment
What would best improve separation by distillation
Heating the distillation flask at a slower rate
DNA replication
Helicase: catalyzes sep of parent DNA strands at origin of rep Ligase: joins 2 DNA fragments Topoisomerase: relieves strain in double helix Primase: joins RNA nucleotides to make primer
when does an enzyme exhibit cooperativity
Hill's coefficient is > 1
After an accident, your physician detected the protein myoglobin in your urine. What type of injury is consistent with this observation? I. Broken bone II. Damaged muscle III. Damaged kidney A. I only B. III only C. I and III only D. II and III only
II and III only Myoglobin is the substance that holds oxygen in the muscles and organs. This observation is consistent with an injury to muscle or organs, but not bone.
List all strong bases
LiOH, NaOH, KOH, RbOH, CsOH, Ca(OH)2, Sr(OH)2, Ba(OH)2
Which amino acids are most likely to be phosphorylated
Serine, threonine, tyrosine (AA's with -OH's)
Caste System
closed status positions that hinder social mobility
John Henry Effect
control group tries harder
gestation
development that occurs between the formation of the zygote and birth of the child
Granular vs Agranular
-Granular (nonspecific): neutro (attack bacteria), eosino (release histamine, parasites, allergic rxn), Baso (allergic rxn, mast cell) Agranular (specific): Lympho (B,T,Plasma) & Monocytes
Hydrophobic interactions have the LEAST significant role in which of the following? A. The secondary structure of globular proteins B. The stability of intracellular vesicles C. The spontaneous formation of micelles D. The immiscibility of oil and water
A. The secondary structure of proteins (globular or not) is determined primarily by local hydrogen bonds; hydrophobic interactions play a more significant role in the tertiary structure of proteins, thus A is the answer.
Which of the following is the best nucleophile? A) Tert-butanol B) Hydroxide ion C) Acetic acid D) Water
B) Hydroxide ion Hydroxide ions are one of the strongest nucleophiles (choice B is correct). Tert-butanol has a large amount of steric hindrance, making it weaker than if it were a primary alcohol (choice A is incorrect). Acetic acid and water are weak nucleophiles (choices C and D are incorrect).
Which of the following describes the manner in which DNA is replicated? A) Conservative B) Semi-conservative C) Dispersive D) Semi-dispersive
B) Semi-conservative DNA is replicated in a semi-conservative manner, meaning each of the two daughter DNAs contains one strand of parent DNA and one strand of new DNA.
A researcher plots pressure versus volume for an interesting chemical reaction. The area under the curve of this plot best represents: A) Temperature increased B) Work done C) Bond dissociation energy D) Heat of fusion
B) Work done The area under a pressure versus volume curve (PV curve) is equal to the work done (choice B is correct; choices A, C, and D are incorrect).
Conversion of a ketone to a secondary alcohol is which type of reaction? A. Oxidation B. Reduction C. Alkylation D. Dehydrogenation
B. Addition of hydrogen atoms and/or removal of oxygen atoms (or bonds to an oxygen atom) is reduction. Removal of hydrogen atoms (like the conversion of an alcohol to a ketone) and/or addition of oxygen atoms (or bonds to an oxygen atom) is oxidation. Note that this is a simple but effective tool to remember; nonetheless the best way to determine whether a reaction is oxidation or reduction is to observe the changes in oxidation state of the compound in question.
A boat horn sounds at 120 Hz. A baritone player plays the same note and hears 2 beats. What frequency is the baritone player's note? A. 60 Hz or 240 Hz B. 118 Hz or 122 Hz C. 30 Hz or 480 Hz D. 116 Hz or 124 Hz
B. Beats is the difference in frequencies arriving at a certain point, creating constructive and destructive interferences. Thus, the frequency of the baritone player could be 120-2 = 118 Hz or 122+2 = 122 Hz.
What is the source of electrons and what is the terminal electron receptor of the electron transport chain in ADP phosphorylation in mitochondria? A. Water, NADP B. NADH, oxygen C. ADP, NAD D. ADP, oxygen
B. NADH is oxidized to NAD+ and to provide electrons for the ETC. Oxygen gas, which has a large reduction potential, is the final electron acceptor and is reduced to water.
What kind of radiation will travel through an electric field on a pathway that remains unaffected by the field? A. A proton B. A gamma ray C. An electron D. An alpha particle
B. Particles with charges will be deflected. The only kind of radiation given that has no charge is a gamma ray. It is pure energy and therefore without charge.
In an SDS-PAGE gel, molecules are separated in terms of A. Charge B. Size C. Hydrophobicity D. Isoelectric Point
B. SDS-PAGE gels immerse molecules in SDS, or sodium dodecylsulfate. SDS gives the molecules relatively uniform negative charge, thus charge does not play a role in the migration of the molecules. The speed at which the molecules can travel is determined by size through the pores of the gel. Larger molecules travel slower than smaller molecules.
B-cell vs T-cell
B: develop in bone marrow, activate in spleen/lymph, antibodies, humoral T: develop in bone marrow, mature in thymus, immune resp, cell-mediated
Types of side chains
Basic: pI = avg pKa for amino group & side chain Acidic: pI = avg pKa for carbox group & side chain Neutral: pI = avg pKa for carbox group & amino group
What are the 4 types of perspectives?
Behaviorist: reward/punishment Humanistic: internal feelings --> happiness Social Cognitive: interaction w/ environment Psychoanalytic: unconscious urge/desire
amide bond
Between carboxylic acids and amines. AKA peptide bond
How do transcription factors work?
Bind DNA to activate RNA pol. DO NOT ACTIVATE RNA POL DIRECTLY!!!
A researcher inhibits several SNARE proteins in a new experiment. Which of the following cellular processes is most likely to be affected? A) Transcription B) Translation C) Endocytosis D) Chromatin remodeling
C) Endocytosis SNARE proteins are essential for vesicle formation, and vesicles are formed during endocytosis in order to engulf extracellular materials (choice C is correct; choices A, B, and D are incorrect).
A researcher identifies a novel chemical compound with the following stereochemical designation at chiral carbons 1, 3, and 7: R, R, S. Which of the following represents an enantiomer to this compound? A) R, R, R B) S, R, S C) S, S, R D) S, S, S
C) S, S, R An enantiomer is the mirror-image, meaning it will have the opposite stereochemistry at each chiral carbon (choice C is correct; choices A, B, and D are incorrect).
Some individuals with blood group A may inherit the genes for blond hair, while other individuals with blood group A may inherit the genes for brown hair. This can be explained by the principle of A. Dominance B. Multiple alleles C. Independent assortment D. Incomplete dominance
C. Independent assortment is the principle that states that genes located on different homologous chromosomes will be distributed independently of each other. This allows for greater variety in the offspring.
Billy throws a ball to Sam, who is standing 5 m away. Which of the following statements is true? A. Billy must throw the ball faster than 10 m/s. B. The ball reaches dynamic equilibrium at the peak of its flight. C. The ball is never at equilibrium during its flight. D. The ball has a kinetic energy of zero at the peak of its flight.
C. The ball is constantly accelerating because of gravity, so it is never at equilibrium. The ball is still moving with a horizontal velocity at its peak so it still has kinetic energy there. The speed at which the ball must be thrown varies by the angle and the distance; in this case the ball need not be thrown faster than 10 m/s.
1Watt (power) =
1J/s power = energy/time
cell potential definition
The difference in potential energy between the anode and the cathode in a voltaic cell
When using labeling for an isotopic substitution, which group do you label?
The one that gets broken off into solution
An individual moving from a salaried corporate attorney position to an hourly wage employee at a retail store has experienced what type of mobility
Vertical (vertical = downward)
What molecular biology should you use to measure the effect of gene deletion coding for a specific protein
Western blot (not southern)
Spreading activation
a method for searching associative networks, neural networks, or semantic networks.
Langerhann cells
antigen-presenting macrophages
reference group
any group that individuals use as a standard for evaluating themselves and their own behavior
implicit attitudes
attitudes that influence a person's feelings and behavior at an unconscious level
Attitude polarization
beliefs become more extreme with additional evidence
noncomp
binds E and [ES] w/ same affinity
What is serum glucose?
blood sugar
removing capacitor 2 from a parallel circuit with 2 capacitors does what to the charge drawn from the battery and the total capacitance of the circuit
both go down
whats the main function of stomach?
breaks down food to chyme
spermatic cord
bundle of fibrous connective tissue containing arteries and veins that runs up the vas-deferens
Amine
can act as H-donor or H-acceptor
common hepatic duct
carries bile from liver to duodenum
gravcity is a ______ force
conservative
in a series circuit with 2 resistors removing the second resistor would do what to the total resistance of the circuit
decrease it
does increasing temp increase or decrease the solubility of a gas in a liquid?
decrease, bc as temp increases, there is more kinetic energy which means the liquid itself will break free from its intermolecular forces and become gas. gas will have too much energy to be soluble/dissolve in liquid!
specific gravity eq
density of object/density of water
benedicts reagent
detects reducing sugars like maltose and hemiacetal groups NOT SUCROSE OR GLYCOSIDIC
Relationship between viscosity and diameter
directly proportional
production of multiple phenotypes is what kinda selection
disruptive selection
concave lense
diverging corrects nearsightedness (myopia can't see far away)
in a parallell circuit with two resistors adding a third parallel resistor would do what to the total resistance
drop it
Specific activity = measure of
enzyme units per miligram of protein
bouyant force
equal in magnitude to weight of fluid displaced -Lower altitude = ↑ pressure/density
what is the major female sex hormone?
estrogen + progesterone
Muscle fiber subtype 2b
fast glyolytic
In human females, mitotic division of oogonia that lead to formation of presumptive egg cells (primary oocytes) occur between: A. fertilization and birth only B. fertilization and puberty only C. birth and puberty only D. puberty and menopause only
fertilization and birth only All of the mitotic divisions that form primary oocytes occur prior to birth
What remains unchanged when a wave crosses a medium?
frequency
what hormone acts systemically to increase protein synthesis and generalize cell function
growth hormone
Kinetic Molecular Theory of Gases
ideal gas has neg volume, no forces, random/elastic collisions, & Temp = avg KE
what is the only time that quaternary structure of a protein exists?
in a protein with more than 1 subunit
Increase in temp does what to Ksp for solids
increase
ideal voltometers have
infinite resistance
informal vs formal sanctions
informal: rewards/punishment formal: recognized & enforced
mixed inhibition? how are Km and Vmax affected?
inhibitor binds to allosteric site in either enzyme or enzyme-substrate complex vmax decreases If inhibitor binds to enzyme, it increases Km (lowers affinity) If inhibitor binds to enzyme-substrate complex, it lowers Km (increases affinity)
How will the rate of a reaction be affected if the catalyst is ground up before being added to the reaction mixture?
it'll be faster because a greater surface area of catalyst will be exposed
alzheimers
loss of memory inability to learn new things
If the level of solution inside a buret is higher than the pressure outside, the pressure level inside the buret is
lower than the pressure outside
How do you generate multiple forms of a protein
mRNA transcripts with multiple combinations of exons must be generated
Quantum #
n (size), l (shape), ml (orientation), ms (spin)
female primary sex organs
ovaries; where eggs are produced
nuclear localization signal
permits proteins to enter the nucleus
field lines for electric field point away from
positive sources
Mechanical energy is
potential + Kinetic
salt bridges do what
prevent charge build up in galvanic cells by releasing ions into separate cells
What are histones? they contain a large amount of what AA?
proteins that DNA wraps around, bc the DNA is negatively charged, histones have + charged amino acids: lysine and arginine
How do we gain heat from the sun
radiation
cog therapy
replace pessimistic attributions with positive ones
Protestant work ethic
represents traditional American values of independence, self-reliance, and hard work
seminiferous tubules
site of sperm production inside the testes
Hemidesmosomes are found in the:
skin
which of the following will affect the frequency of sound waves traveling through the air as measured by a detector
speeed of the source of the sound
main function of the rectum
storage
main function of gallbladder
store bile
Epididymis
stores sperm; get mitochondria + flagella
low Km = [strong/weak] binding of substrate .˙. [product/substrate] is favored
strong binding = products favoured
Principle quantum number is associated with
the approximate size of the electron cloud
Operon
transcribed from single promoter
How is fat transported in the blood?
travels freely in lipid bilayer & is attached to polar molecule (protein) when traveling through blood
corpora cavernosa
two columns of erectile tissue found in the shaft of the penis
what is a concentration cell?
type of galvanic cell in which the only difference is concentrations, even the 2 substances are the same (eg. zinc both in anode and cathode, just diff concentrations)
Cytotoxic T cells target
viral antigens on the surface of viral-infected cells
A sunk object displaces its
weight
How is pepsin activated?
when pepsinogen interacts with HCl in the stomach
when do we use complex splitting? equation)
when the H is being split by 2 or more neighbouring groups eg of 2 neighbours causing splitting: (na+1)*(nb+1)
Topoisomerase
winds unwinds for synthesis
Can all eukaryotes be seen by a light microscope?
yes! this means they must be greater than 200 nm b/c that is the limit of resolution of a light microscope so can most bacteria
you make more lactic acid when you are in or out of shape
you make more of it when you're not in shape
Z is
zame zide
Filtration
Initial filtration at glomerulus is due to: passive flow due to pressure difference
Where are digestive enzymes found?
Lysosome (acidic pH)
If a marker is most active during mitosis, what function must it have in gene expression
Marking gene for reactivation after mitosis
What part of the cell would have the lowest fluorescence level during apoptosis
Mitochondria because it loses membrane potentia;
The energy released when an atom splits comes from
Mutual repulsion of the fragments
Dopamine is most likely to influence what type of conditioning?
Operant conditioning. This is most associated with reward-seeking
How does vasoconstriction affect the ratio of F-actin: G-actin
Relative amount of G-actin decreases. Monomers of G-actin polymerize into f-actin to maintain pressure Mediated by microfilaments
Scalar vs vector
Scalar (magnitude): speed, friction, distance Vector (magnitude & direction): displacement, velocity, force, acceleration
What psychological concept best explains observed responses in the IAT?
Schemas
point mutation
Silent (no effect), Nonsense (stop codon), Missense (codes for diff acid)
Why are the percentages of the change in frequency and wavelength greater when sound waves are used instead of radio waves?
Sound waves travel more slowly. Doppler equation is delta f/f = -v/c So frequency shift inversely proportional to speed of wave in the medium in which it propagates. Sound has smaller velocity so the change in frequency and wavelength is greater.
intron vs exon
Intron is a noncoding region, an exon is a coding region
stranger anxiety
begins at 8 months of age
Limit of resolution of a light microscope
200 nm
isoprene structure
5 carbon
tRNA sites
A (amino acid) ---> P (peptide) --> E (exit)
purines
A,G
list posterior pituitary hormones, are they tropic or direct?
ADH and oxytocin; these hormones are actually made by the HYPOTHALAMUS but stored and released in the posterior pituitary DIRECT.
hydrophobic amino acids (long alkyl side chains)
ALA, VAL, LEU, ISO, PHE, PRO, MET, TRP, GLY (side chain is single H atom)
Anomeric C
C 1
Kidney
Cortex: ↓ solute [ ] Medulla: ↑ solute [ ]
is gibbs free energy an intensive or extensive property? what does that mean?
EXTENSIVE aka it depends on HOW MUCH you're dealing with!! aka quantity
non polar amino acids
Glycine, Alanine, Valine, Leucine, Isoleucine, Methionine, Phenylalanine, Tryptophan, Proline
glycogen, cellulose, glucose bonds
Glycogen: alpha-1,4 glycosidic bond Cellulose: Beta-1,4 glycosidic bond Glucose: alpha-1,6 (branching)
hydrophilic amino acids (charged side chains)
HIS, ARG, LY, GLUT (amide), ASP, SER, CYS, THRE,
Thomas thereom
If people believe something is real, then it is real in its consequences
metal and halide shortcut for ksp
MX: Ksp = x^2 MX_2: Ksp = 4x^3 MX_3: Ksp = 27x^4
what makes the blood vessels to dilate in the penis during an erection?
PARASYMPATHETIC system; NO - nitric oxide
Comparative pessimism vs Comparative optimism
Pessimism: believes they are more at risk/worse off than others Optimism: believes they are less at risk/better off than others
Oogenesis
Prophase I: Primary oocytes Metaphase II: Secondary oocyte Meiosis II: Ovum
Eye functions
Pupil: expands/contracts based on how much light taken in Retina: storing & processing images (rod/cones are photoreceptors for light detection) Lens: direct light Cornea: gather & use light
Renin system
Renin: released during ↓ BP Cortex: releases aldosterone Aldosterone: restores blood by ↑ Na+ absorb & ↓ K+/H+
isoelectric point
The pH value at which the amino acid has a 0 charge
what is the function of membrane protein?
acts as receptors + carrier molecules
as Q increases, what happens to the cell potential?
decreases
sublimation
from solid to gas
hypergenic
image behind retina farsightedness
when do we NOT expect to see spin-spin splitting?
in chemically equivalent protons
thyroid gland
its hormones + affects metabolism - hormones: T3 + T4
how does an enrol form?
ketone or aldehyde + H+ or OH- ====> enrol
SDS-PAGE separates proteins based on
mass and affinity
Mesoderm
muscles, circulatory, reproductive, & excretory systems
Glycine
non-chiral, inactive
Exchange theory
people are motivated by self-interests in their interactions with other people (cost-benefit analysis)
sensitive period
point in early development that has significant influence on physiological & behavioral functions later on in life
Terminal electron acceptor for lactic acid fermentation
pyruvate
phosphotase
removes phosphate group -GTP --> GDP
what stabilizes a peptide bond?
resonance delocalization between the N and O
Chemoreceptors
respond to chemical
Mechanoreceptors
respond to touch, pressure, vibration, stretch, itch (hair cells)
Where is the pancreas located?
retroperitoneum
how is calcium reabsorbed?
secondary active transport; anti-port
Keq greater than 1 means
spontaneous
cognitive
steryotypes already thoughts and beleifs
when LH is high
the High LH is responsible for ovulation
Red Blood cell organelle fact
they don't have mitochondria thus no electron transport chain they must produce energy anaerobically they also don't have a nucleus
Function of an ebulliator
to prevent superheating of fluid to be distilled
pressure can change without
volume changing therefore work isn't done`(isochoric process)
pituitary gland
what hormones it makes and their function + - "master gland" - gets stimulated by the hypothalamus and in turn directs it to all endocrine glands in the body
Le Chatlier's Principle: Pressure
↑ pressure (↓ volume) shifts reaction to side with fewer moles -Favor products if [ ] is kept low
steryotype threat
a self-confirming concern that one will be evaluated based on a negative stereotype
lewis base does what
donates electrons lewis acids accept electrons
When does oogenesis begin?
during embryonic development
Aerobic vs anaerobic
-Aerobic: produces more ATP, cellular resp, 38 ATP, higher growth rate -Anaerobic: produces less ATP, fermentation, 2 ATP, lower growth rate
Types of solution
-Hypotonic: swelling -Hypertonic: shrivel
Skeletal muscle fibers
-Red (slow): ox phos, ↑ mito/myoglobin, aerobic -White (fast): ↓ mito/myoglobin, anaerobic
which 2 muscles help the scrotum in maintain good temp for testes?
1- cremaster 2- dartos
2 female urethra
1- internal urethral sphincter - smooth 2- external urethral sphincter - skeletal
What nucleic acid is present in HIV? A) ssRNA B) ssDNA C) dsRNA D) dsDNA
A) ssRNA HIV is a retrovirus, so its genome is encoded with single-stranded RNA.
Fatty acid synthesis steps
Activation --> Bond form --> Reduction -> Dehydration --> Reduction
Bases vs acids
BL base: accepts proton BL acid: donates proton Lewis base: donates e-. Has lone pairs Lewis acid: accepts e-
Why would you use BSA in a kinetics experiment
BSA would prevent the enzyme from adhering to the walls of the vessel
Which of the following is a hormone likely to trigger a second messenger cascade? A. Aldosterone B. Cortisol C. Somatostatin D. Progesterone
C. A second messenger cascade is a series of events that occurs intracellular following the binding of a hormone to a membrane receptor. Thus, in order for this to occur, the hormone must be a hormone that binds to a receptor on the plasma membrane. Thus, the hormone does not enter the cell. Peptide hormones do not enter the cell. Thus, the correct answer will be a peptide hormone. Choice C is correct since all the other hormones have an -one or -ol ending, indicating they are steroid hormones.
Hydroxyapatite formula
Ca(PO4)6(OH)2
magnetic fields go from __ to ___
N ===> S
Can an element at its lowest oxidation state be reduced?
NO!
Electric field
Points from positive to negative
Panic attacks act as
Positive punishers
When do we assume causality for MCAT questions
When independent precedes dependent (ok to assume causality on MCAT questions)
2 functions of mouth glands
1- release serous content (enzymes) 2- release mucin
what are products of fatty acid breakdown that enter the TCA cycle
acetyl-CoA
Esterification
acid + alcohol --> ester + water
Floppase
move lipids from inner to outer membrane
Evolutionary Stable Strategy (ESS)
natural selection will prevent other strategies from arising
deprotenated means what with solubility
not not very soluble
the image in the retina is
not real, reduced in size and inverted
maintaining a phenotype is what kind of selection
stabilizing selection
Lens
-Diverging: spread out light --> brings it closer to retina Focal (-) : Virtual and reduced. Object longer than focal. -Converging: unites light --> brings it farther to retina
Brain
-Prefrontal cortex: control aggression -Hindbrain: balance (Cerebellum, medulla, RF) -Midbrain: survival skills (inferior- startle reflex & superior colliculi) -Forebrain: thalamus, hypothalamus, basal ganglia (posture), limbic system, cerebral cortex/cerebrum (cognitive function)
What is one primary difference between the autonomic and somatic nervous system?
-Somatic: 1 neuron -Autonomic: 2 neurons (preganglionic & postganglionic)
Fertilization
-ampulla of fallopian tube -release Ca2+ which ↑ metabolic rate & prevents other sperm from entering -Cortical rxn
what 2 ways does the GI tract regulate itself?
1- gastro-colic reflex: when food enters the stomach, it initiates a response that prepares the intestine to start contracting .˙. pushing the food already there down south 2- hormonal control
effective nuclear charge (Zeff) definition and equation
is the net positive charge experienced by valence electrons. It can be approximated by the equation: Zeff = Z - S, where Z is the atomic number and S is the number of shielding electrons
Population validity
is your sample similar to the population whom you wish to generalize?
Which of the following is NOT an acceptable name for citric acid? A. 2-hydroxypropane-1,2,3-tricarboxylic acid B. 3-carboxy-3-hydroxypentanedioic acid C. 2-hydroxy-1,2,3-propanetricarboxylic acid D. 1-carboxy-2-hydroxypentanedioic acid
D. If the acid were named as a dioic acid with a 5-carbon root chain, the carboxy group named as a substituent would occur on carbon number 3, not carbon number 1.
Electron vs current flow
Electron: Anode --> Cathode Current: Cathode --> Anode
2 types of geometry
Electronic (bonding + antibonding) & Molecular (bonding)
People who are able to delay gratification have which type of intelligence
Emotional
Experiments
Griffith: non-virulent bacteria (heat) Avery: DNA degradation (bacteria) Hershey: radio-labeled DNA (bacteria infected)
common ion effect won't change _____ only ____
ksp molar solubility
Work =
Pressure* V displaced
Blood
RBC: erythrocytes. anaerobic. bone marrow. NO nucleus/DNA WBC: leukocytes. Bone. Immune system Platelet: thrombocytes. No nucleus. Megakaryocytes, Coagulation
Path of sperm from seminiferous tubules
Seminiferous tubules --> Rete testis --> Epididymis to mature
Requirement for magnetic moment
odd number of neutrons plus protons
tunica albuginea
prevents the penis from over-filling during an erection
purpose of intrinsic longula muscles?
shorten or widen tongue
Muscle fiber subtype 2 a
slow glycolytic
bystander effect
the tendency for any given bystander to be less likely to give aid if other bystanders are present
question order bias
the tendency for earlier questions on a questionnaire to influence respondents' answers to later questions
glass escalator effect
the tendency for men seeking or working in traditionally female occupations to benefit from their minority status
Catalyst
-Homogenous: if it can't be removed from products, products will be contaminated -Heterogenous: If it's ground up, reaction rate will increase because there is a greater surface area
Polarized light
-Plane: parallel, unpolarized light through polarizer -Circ: rotating, equal intensity, unpolarized light through pigment/filter
1 spermatocyte makes how many functional sperm?
4
When glycerol reacts with there different fatty acids, how many sterogenic centers does the product triacylgycerol contain? A. 0 B. 1 C. 2 D. 3
B. When glycerol reacts with three different fatty acids, only carbon 2 in the resulting triacylglycerol is attached to four different groups
How can we eliminate stereotype threat?
By making people aware of it
A participant is able to identify a leopard in an image in which most of its body is occluded by branches. Which of the following principles aid(s) in this identification? I. Top-down processing II. Bottom-up processing III. Gestalt processing A. I only B. II only C. I and III only D. II and III only
C. Choice C best describes this scenario. Top-down processing refers to the brain's ability to recognize an entire animal without having to analyze its individual parts. Gestalt principles are also at work here, helping to determine the animal's outline through "good continuation."
What mass of CDP (403 g/mol) is in a 10 mL solution of a 16mmol concentration? A. 6.4 x 10^-4 B. 6.4 x 10^-3 C. 6.4 x 10 ^-2 D. 6.4 x 10^-1
C. (16 x 10^-3 mol/L) x (403 g/mol) x (.001 L) = 6.4 x 10^-2
Which of the following hormones undergoes positive feedback? A) Insulin B) Glucagon C) Melatonin D) Oxytocin
D) Oxytocin Positive feedback occurs when the presence of a certain hormone leads to a further increase in its amount. Oxytocin undergoes positive feedback during childbirth.
Endocrine signal pathway
Hormone --> Blood --> tissue --> Receptor --> Gene
What is the anus composed of?
Internal and external anus sphincters internal: smooth muscle external: skeletal
How do you describe the movement of an electron after it is ejected from the cathode?
It accelerates toward the anode
what in the kidney is responsible for exchange with the Vasa Recta and the adjustment of solute amounts in the urine
Loop of Henley
Amino acids
Lower + charge: elute at ↓ pH Higher + charge: elute at ↑ pH
Delayed ovulation, as a cause of tubal pregnancy, would most likely be associated with delayed secretion of which of the following hormones? A. Progesterone B. Luteinizing hormone C. Estrogen D. Human Chorionic Growth hormone
Luteinizing hormone because is the hormone responsible for triggering ovulation.
What process occurs during mitosis but NOT during meiosis 1
Splitting of centromeres
what hormone promotes the synthesis and release of the thyroid hormones
TSH
For size exclusion chromatography, we consider urea to be
a small compound (elutes last)
negative pressure breathing
as lung expands (by using diaphragm and external intercostal muscles) volume ↑, pressure ↓ & air is drawn into the lungs
social constructionism
ascribe meaning or value to objects
Acidic amino acids
aspartate, glutamate
In galvanic cells what goes to what side
cations to cathode anions flow to the anode in order to maintain neutrality or to keep the solutions neutral
pressure and solubility of gases in liquids have a _______ relationship
direct if the solubility of oxygen gas in water is 1.25x10^-3 and in a city high above the sea level where atmospheric pressure is .8 it must be 1.00x10^-3 because thats 80 percent of what it is at sea level
what amino acid is the only one without a chiral center therefore is not optically active
glycine you can tell if it all contains glycine when you know under polarized light to determine if the whole acid is optically active or not
Highest amino acid melting point is the amino acid that
is the largest with most likely to dipole dipole
Lower left periodic table trend
larger the atomic radius
Vicarious learning
learning by seeing the consequences of another person's behavior
2 key regulators during oxidative phosphorilization
limited ADP or low Oxygen
Kcat
limiting rate of enzyme catalyzed reaction at saturation
what is the pathway of food from mouth?
mouth ==> oesophagus ==> stomach ==> small intestine ==> large intestine (colon) ==> rectum ==> anus
Without conscious effort, people are unlikely to automatically visually process
novel info (space, time, & frequency of events are processed automatically)
Types of groups
primary (peer) and secondary (impersonal)
what holds together nucleus
strong nuclear force holds protons together
what is integration in an NMR spectrum? how do you find it and what does it mean?
the area under each signal, tells us how many protons correspond to the specific signal. - out of all the numbers given, find the smallest value, then divide all the numbers by it and the result is how many protons each signal corresponds to
Collectivism
the practice or principle of giving a group priority over each individual in i.
What does glycine usually form hydrogen bonds with
the protein backbone (not side chains)
beta
+ has too few neutrons ===> top remains the same, bottom loses 1
chief cells
- found in stomach -secretes pepsinogen
Translation
-Begin at codon MET, binds to small ribosomal subunit before assembly, & involves post-translational processing
Adrenal cortex vs Adrenal medulla
-Cortex: Glucocorticoid (stress, immune), Mineral (aldosterone), Cortical (androgen/estrogen) -Medulla: catecholamine. Epinephrine/Norepinephrine. SNS. Glycogenolysis
Types of studies
-Cross-sec: exposure & outcome measured at same time -Case-control: outcome then exposure history -Cohort: exposure then outcome
Fission reactions
-Energy --> Nucleus -Neutrons don't experience electrostatic repulsion
HPG axis (Females)
-Hypothalamus produces GnRH -GnRH stim anterior pituitary to produce FSH & LH -FSH --> estrogen -LH --> progesterone
Dermis
-Merkel cells: deep pressure & texture -Free nerve endings: pain -Meissner corpuscles: light touch -Ruffoni endings: stretch -Pacinion corpuscles: deep pressure & vibration
Implicit memory (unconscious)
-Procedural: skills/tasks -Priming, conditioning
Types of muscle
-Skeletal: striated, voluntary, polynucleated -Smooth: nonstriated, involuntary, uninucleated, myogenic -Cardiac: striated, involuntary, uni/binucleated, myogenic
Techniques
-Southern blotting: isolate DNA (DOES NOT ANALYZE GENE EXPRESSION) -RT-PCR: measures mRNA levels -Western blotting: analyze posttrans modification (proteins, acetylation) -Northern blotting: detect RNA -ELISA: isolate specific protein -Centrifugation: sep by mass -Isoelectric focusing: sep proteins based on pI. must establish a -stable pH -SDS-page: separate proteins by mass.
ADH
-antidiuretic (↓ water excretion). -Peptide hormone -Produced: hypothalamus -Secreted: Anterior pituitary -Released by: posterior pituitary -Released during: Dehydration & ↑ blood osmolarity -↑ absorption, ↑ volume, ↑ pressure,
General Adaptation Syndrome (GAS)
-body's adaptive response to stress -alarm --> resistance --> exhaustion.
NMR spectrum ranges:
0.5-2: methane/fully shielded 2-2.5: H that's bound to a carbon thats bound to a carbon with an EN molecule eg: o=c-c-h
How many H bond donors and acceptors does A have?
1 donor, 1 acceptor
How many H bond donors and acceptors does T have?
1 donor, 1 acceptor
How many H bond donors and acceptors does C have?
1 donor, 2 acceptors
esterification steps
1) acid protonates the oxygen of the carboxylic acid, making the oxygen +1 2) the resonance structure takes over where the oxygen d- bond becomes single and the carbon gets a + charge
2 ways of peptide cleavage/breakdown?
1- acid hydrolysis: non-specific 2- proteolysis: specific, uses proteases - eg: trypsin
Coagulation cascade
1.) Prothrombin converts thromboplastin --> thrombin 2.) Thrombin converts fibrinogen --> fibrin 3.) Platelet forms
trialglycerol
3 fatty acids linked to single glycerol
How many teeth do adults have?
32 teeth
Which of the following changes to a circuit will decrease the electric field between a cathode and an anode by the greatest amount? A. increasing the distance of the electrodes by a factor of 2 B. decreasing the distance of the electrodes by a factor of 2 C. increasing the resistance by a factor of 2 D. decreasing the resistance by a factor of 2
A. for a fixed voltage between a cathode and anode, the electric field is inversely proportional to the distance between them. E = (V-IR)/L
Source of phosphates used by kinases
ATP (NEVER ANSWER KINASE ITSELF!!!)
Meritocracy
Achieved > Ascribed status -level of opportunities, social mobility -talent + effort
Which of the following best describes the definition of a Lewis base? A) Electron pair acceptor B) Electron pair donor C) Proton donor D) Proton acceptor
B) Electron pair donor A Lewis acid is an electron pair acceptor (choice A is incorrect). A Lewis base is an electron pair donor (choice B is correct). A proton donor is a Bronsted-Lowry acid (choice C is incorrect). A proton acceptor is a Bronsted-Lowry base (choice D is incorrect).
What is the primary function of the nucleolus? A) Store genetic information in the form of DNA B) Synthesize rRNA C) Telomere extension D) Transcription of actin
B) Synthesize rRNA The nucleolus is where rRNA is synthesized and plays an important role in ribosome assembly. Genetic information is stored primarily outside of the nucleolus in the nucleus (choice A is incorrect). Telomere extension and actin transcription are not primary functions of the nucleolus (choices C and D are incorrect).
E coli produces vitamins. If the E. coli population in the colon is severely reduced to due to extended antibiotic treatment, which of the following effects on digestion and nutrition are most likely to occur. A. deficiencies of necessary digestive enzymes B. deficiencies of specific vitamins C. intestinal tract infections due to increased bacterial populations D. greatly reduced absorption of caloric nutrients
B. E. coli produce vitamins. Absorption of caloric nutrients doesn't occur in the colon, occurs in the small intestine only
An enzyme that requires Mg2+ for its catalytic activity and is currently bound to the Mg2+ is called which of the following: A) Zymogen B) Apoenzyme C) Holoenzyme D) Coenzyme
C) Holoenzyme An enzyme with its cofactor, Mg2+ in this case, is called a holoenzyme (choice C is correct; choices A, B, and D are incorrect).
where in the cell do steroid hormones bind?
CYTOPLASM. - since they are fat-soluble, they can cross the membrane, but are then bound to carrier proteins in the cytoplasm which takes them into the nucleus *THEY DO NOT BIND AT THE NUCLEUS*
Changes in bodily sensations in responses to a stimulus acts as
Conditioned stimuli
Convection vs conduction
Convection: direct contact, transfer of heat Conduction: heat carried away (steam, smoke)
How is estrogen made?
Converted from testosterone!!!
Types of lens
Convex: converge, r (+), f (+), Farsighted Concave: diverge, r (-), f (-), Nearsighted
Which of the following structures is NOT derived from the ectoderm during human development? A) Skin B) Neurons C) Pigment cells D) Muscle cells
D) Muscle cells Muscle cells are derived from the mesoderm. Skin, neurons, and pigment cells are derived from the ectoderm (choices A-C are incorrect).
Hippocampus stores what type of memory?
Episodic (explicit)
which hormones are tropic and which are direct?
FLAT PEG - tropic (anterior pituitary): FSH, LH, ACTH, TSH - direct: prolactin, GH, endorphins
Complex's
I: NADH dehydrogenase (ETC) II: succinate dehydrogenase (Krebs) --NO protons III: Cyt-C oxidoreductase IV: Cyt-C oxidase
does chloride flow in or out of the cell?
IN the cell
E cell and Delta G have a what relationship
Inverse
What methods separate proteins based on their charge
Isoelectric focusing Ion-Exchange chromatography
How does the kidney get rid of nitrogenous wastes?
It acts the urea transporter which removes urea from the interstitium and transports it back to the ascending loop of henle
What does it mean for an assay to be highly specific?
It can readily distinguish between this reaction and others
Emotional theories
James-Lange: Arousal -> response -> emotion Cannon-bard: Arousal + response --> action (same time) Schachter-Singer: arousal & interpret --> response
∆G unit
Joule
does cones AP directly synapse ganglion cells?
NO
Does doppler shift depend on distance?
NO only relative speed
Digestion pathway
Oral cavity --> Pharynx --> Esophagus --> Stomach --> Small intestine --> Large intestine --> Rectum
What pathway is phosphogluconoate involved in
PPP
Phosphatidyl choline belongs to what class of biological molecules
Phosphatides
degree of unsaturation/HDI formula
U = (how many hydrogens it's supposed to have - how many it actually has)/2 Non-CH molecules: *NITROGEN acts as 1 carbon and 1 hydrogen * OXYGEN is ignored *halogens: F, Cl, Br, I = count as one hydrogen
third law of thermodynamics
a perfect crystal at zero kelvin has zero entropy
social exclusion
a sense of powerlessness when individuals feel alienated from society
blood flow is ___ throughout body blood pressure is ___ throughout body
constant, not constant
Where does most digestion occur?
duodenum (first part of small intestine)
isobaric on pressure vs volume graph
horizontal line
Pygmalion effect
interchangeable with "self-fulfilling prophecy"
what kind of cells make up the endocrine pancreas?
islet cells
low sexual dimorphism
males/females resemble eachother
source monitoring error
misidentifying source of memory
on galvanic cells the electrons flow from the what to what
negative end(anode) to the positive end (cathode)
exothermic
negative enthalpy
Is Ka needed in titrations
no
ER
protein translation
self-fulfilling prophecy
refers to the idea that people will behave in a way that confirms the expectations of others or their own expectations AKA A self-fulfilling prophecy occurs when a prediction comes true because it is believed to be true and thus inspires behavior, attitudes AKA phenomenon in which a person unconsciously behaves in such a way as to fulfill people's beliefs about him or her.
Acculturation
refers to the process of adopting elements of one's new host culture that differ from one's native culture. aka assimilation
Why are sunscreens like zinc oxide so effective at preventing sunburn?
reflect light
variable ratio
reinforces response after unpredictable # of responses
How does freeze-drying proteins work
sublimation under reduced pressure
alpha D glucose and Beta D glucose are different how
the hemiacetal carbons have opposite configurations
What is boiling point?
the temp at which the vapour pressure = atmospheric pressure
Thermodynamic laws
zero: no heat flow (q constant) 1st: Energy conserved 2nd: energy dispersed in closed system
what kind of of fatty acid creates a kink?
cis
Enantiomers
isomers that are mirror images of each other, non-superimposable (L and D)
whats commonly associated with an accumulation of NADH in respiratory control?
citric acid cycle inhibition
As harmonic number increases, what happens to period, frequency, and wavelength
frequency increases period and wavelength decrease
a spontaneous rxn in a voltaic cell has a ___ ∆G value and a __ E cell value
-, +
delta G reaction =
-RT(lnKeq)
Action potential time duration
1 milisec
ionizable groups
Amide, Imide, Phenol, Carbox acid
does H3O act as an acid or base?
it would become h2o + H+ .˙. acting as an acid
components of cell membrane
phospholipids, proteins,, cholesterol
GH
synthesized & secreted by anterior pituitary
Epithelial cells are connected by:
tight junctions (prevent fluid leakage & are found in BBB)
Frequency vs intensity of light
-Freq: determines KE of ejected e- -Intensity: determines # of e- ejected per time
Cytoskeleton
-Microfilament (actin): protect cell & contract using myosin -Microtubule (tubulin, kinesin, dynein): Motor protein pathway. cilia & flagella, intracellular movement, flexible. Originate from centrosome -Intermed filament: Adhesion & anchor (keratin)
Bone
-Osteoblast: build bone -Osteoclast: break bone (polynucleated cells) -Osteocyte: maintain bone (mature cells) -Chondrocytes: cartilage (chondrin) -Bone marrow: produce blood -Haversian canal: capillary, nerves, blood vessel -Lacunae: empty spaces as result of cell death -Bones are degraded in areas of low stress & built in areas of high stress -Periosteum: attach bone to muscle, connective tissue, surrounds long bone
PDH
-Pyruvate --> Acetyl-CoA -Rate limit: PDH -Produce: 2 NADH -Stim by insulin, Inhib by Acetyl-CoA/NADH -post-exercise
Gel electrophoresis
-The further DNA travels down, the shorter it is (5' end) -2 bands under reducing conditions --> Disulfide bonds composed of multiple subunits
for each round of beta oxidation _____ molecules of NADH will be produced
1
1 volt =
1 J/C
list all steroid/terpene derived hormones
1) sex hormones: - estrogen (female sex); estradiol, estrone - progesterone; pregnancy hormone - androgens (male sex); testosterone, androsterone 2) adrenal CORTEX hormones: - cortisone + cortisol ==> stress hormones - aldosterone ==> regulates BP
Skeletal muscle contraction
1.Acetylcholine binds to receptor at neuromuscular junction 2. Action potential travels down T-tubule 3. Ca2+ release from sarcoplasm 4. Ca2+ binds to troponin (actin & myosin cross bridge) 5. Acetylcholine removed from synaptic cleft 6. Ca2+ goes back to sarcoplasm 7. Tropomyosin binds to actin (detaches cross bridge)
every __m you dive, you get an additional ___ kPa on you
10, 101
Egalitarianism
A belief in the equality of all people
What is a sphincter?
A circular muscle that constricts or dilates to regulate the passage of materials through an opening
Deindividuation
A phenomenon that occurs when immersion in a group causes people to become less aware of their individual values
Which waves are most likely to be experienced during stage 3 of sleep? A) Delta B) Theta C) Beta D) Alpha
A) Delta Delta waves are experienced during stage 3 of sleep (choice A is correct). Theta waves are experienced during stage 2 of sleep (choice B is incorrect). Beta waves are experienced during wakefulness (choice C is incorrect). Alpha waves are experienced during stage 1 of sleep or relaxation (choice D is incorrect).
Connexin43, or Cx43, can directly transmit signals between cells. Based on this information, what type of junction does Cx43 most likely form? A) Gap B) Tight C) Desmosome D) Hemidesmosome
A) Gap Cx43 is a connexin protein as stated by the passage, and connexins form gap junctions, which mediate direct signal transmission (choice A is correct; choices B, C, and D are incorrect).
Which of the following hormones increases glycogen storage? A) Insulin B) Glucagon C) Somatostatin D) Melatonin
A) Insulin Insulin is involved in the uptake and storage of blood glucose, and this is partially achieved through the storage of glucose as glycogen (choice A is correct). Glucagon breaks down glycogen stores (choices B is incorrect). Somatostatin blocks both insulin and glucagon (choice C is incorrect). Melatonin is involved in sleep (choice D is incorrect).
Which of the following amino acids is MOST likely to favorably interact with the DNA backbone? A) Lysine B) Glutamic acid C) Valine D) Proline
A) Lysine Lysine is positively charged and can interact with the negatively charged phosphates on the DNA backbone. Glutamic acid is negatively charged and will repel from the negatively charged phosphates (choice B is incorrect). Valine and proline are uncharged and nonpolar, so they will not form strong interactions with the DNA backbone (choices C and D are incorrect).
Which of the following blood types is the universal donor? A) O B) A C) B D) AB
A) O Type O blood is the universal donor because it does not have surface antigens that will be considered foreign by the A or B antibodies (choice A is correct; choices B, C, and D are incorrect).
Researchers decide to interrupt a protein-RNA interaction in a rat model without using a small molecule inhibitor. Which of the following will most likely disrupt the interaction? A) SiRNA against the RNA B) Radiation against heptanol C) Acetyltransferase specific for β-actin D) Plasmid producing the protein
A) SiRNA against the RNA SiRNAs bind to mRNAs for certain genes and lead to degradation. If the mRNA is degraded, the protein will no longer be able to interact with the RNA (choice A is correct). Radiation is highly non-specific and would likely affect other processes (choice B is incorrect). β-actin is not definitely involved in the protein-RNA interaction based on information from the passage (choice C is incorrect). A plasmid producing the protein would likely not be taken up by the rat cells, and an increase in protein expression should not disrupt the interaction (choice D is incorrect).
Which of the following compounds would have the highest boiling point? A. 2-methylhexane B. 2,4-dimethylpentane C. 2,2,3-trimethylbutane D. 2,2-dimethylpentane
A. 2-methylhexane has the most surface area than any of the other molecules because this molecule is the least branched and most linear in structure. These hydrogens undergo weak dipole moment interactions and thus will raise the boiling point as compared with a molecule of the same molecular weight (in terms of carbons) but with a lower surface area.
Alcohol dehydrogenase, the enzyme responsible for metabolizing ethanol into acetaldehyde, is a type of oxidoreductase. What cofactor will be used to facilitate this reaction? A. NAD⁺ B. NADH C. ATP D. FADH₂
A. Alcohol dehydrogenase uses an electron carrier to accept the electrons taken from ethanol. It must oxidize the primary alcohol ethanol into an aldehyde. This means that a hydride will be lost requiring a cofactor that can be reduced. NAD⁺ is reduced to NADH here, and choice A is correct.
The luteal surge is largely due to a positive feedback loop between which of the following hormones? A. Estrogen and LH B. Estrogen and FSH C. FSH and LH D. LH and prolactin
A. As LH levels rise in the follicular phase of the menstrual cycle, estrogen levels are stimulated to increase. Estrogen in turn stimulates the release of LH, which results in a positive feedback loop that causes the luteal surge prior to ovulation.
Two proteins from different species are found to have substantially different amino acid sequences and are not homologous. Yet, these two proteins carry out nearly identical function. This is an example of: A. convergent evolution. B. divergent evolution. C. coevolution. D. None of the above; the terms A-C are used only to describe homologous structures.
A. Convergent evolution is used to describe analogous structure and function rather than homologous structure and function. For example, the evolution of the wing is convergent evolution. These structures are analogous since they are similar in structure and function but they are not homologous since they evolved separately.
Which of the following statements about endocrine glands is true? A. They are ductless. B. They secrete autocrines. C. Very few, if any, of its hormones are steroid-based. D. All endocrine glands are derived from endoderm.
A. Endocrine glands secrete their products directly into the bloodstream, hence they are ductless. Autocrines act on local targets and are not considered to be part of the endocrine system. Most of their hormones are steroid-based. Some endocrine glands are derived from mesoderm.
Which of the following rate laws is most likely to have the rate constant with the largest magnitude, assuming that all the associated reactions are elementary? A. k[H₂][O₂] B. k[Fe]⁴[O₂]³ C. k[H₂]²[O₂] D. k[Cl₂][Na]²
A. In the four options, the rate laws imply, respectively, a reaction dependent on two, seven,four, and three collisions. Two collisions is far more likely than three,four, or seven, therefore we can see that it is most likely that (a) will have the largest magnitude in its rate constant.
Which of the following types of visual search primarily consists of parallel processing? A. Feature Search B. Pre-Attentive Search C. Focused Attention Search D. Conjunctive Search
A. One may begin this question by eliminating options B and C, as these are both stages of visual processing (not types of visual search per se). A conjunctive search is one in which the target object shares relevant visual features with distracter objects. For example, if the target were a green circle, the distracters could be green squares and blue circles. This would require using knowledge of both the shape and the color of the object to find the target. This confluence of the features of a shape occurs with focused attention, and is thus done in serial. In contrast, in the feature search one single feature (e.g., color) distinguishes the target from the distracter objects. A single feature search can be done in parallel because combination of multiple features (and thus focused attention) is not needed. Thus, the answer is (A).
Within the first several seconds of nicotine intake, the adrenal medulla is stimulated. Which of the following would be released into the bloodstream as a result? A. Epinephrine B. Serotonin C. Acetylcholine D. Endorphins
A. The adrenal medulla is responsible for the release of epinephrine. Even without this knowledge, smoking is responsible for stimulating the sympathetic nervous system, which regulates the body's "fight or flight" response. Of the choices, only epinephrine is associated with arousal.
Immunoglobulins that trigger different responses by the immune system differ by their: A. Constant region B. Antigen-binding site C. Antigen D. Variable region
A. The constant region of the immunoglobulin heavy chain determines the isotype (e.g. IgD, IgG, etc.). Each isotype triggers the immune response in a different way. However, different antibodies within an isotype will vary at their antigen-binding site or their variable region but still trigger the immune system based on their isotype.
A patient which renal failure has nephrons which lack the ability to actively secrete or reabsorb any substances. Which of the following actions will the patient's kidney most likely still be able to perform? A. Excretion of salt in urine B. Production of hypertonic urine C. Regulation of blood osmolality D. Conservation of glucose
A. The fluid in Bowman's capsule is isotonic to plasma. Without reabsorption or secretion, isotonic urine can still be produced. In other words, this patient's nephrons filter the blood at the glomerulus, but that initial filtrate then becomes urine without any further modification. This process will still allow excess salt to be removed from the body, because that salt diffuses through the glomerulus, which is still functioning in this patient.
Which type of hypersensitivity is mediated by IgE? A. Type I B. Type II C. Type III D. Type IV
A. Type I hypersensitivity is IgE mediated. This type is commonly known as allergy, normally occurring in reaction to harmless environmental allergens. Types II and III are disorders mediated by IgG and IgM, often associated with complement. Type IV is mediated by T lymphocytes and is antibody-independent.
Once complex behaviors are learned, they can be maintained using different schedules of reinforcement. Which type of schedule produces highest response rate? A. Variable schedule B. Fixed schedule C. Ratio schedule D. Interval schedule
A. Variable ratio schedules present reinforcement at a variable rate. The variable ratio schedule is most resistant to extinction because one does not know exactly when one will be reinforced therefore one keeps responding.
An object is pushed off of a cliff 17 m high. If the cliff had been 34 m high, how would the object's final velocity at the ground be affected? A. It would increase by a factor of √2. B. It would increase by a factor of 2. C. It would increase by a factor of 4. D. It would not be affected.
A. We can simplify mgh = ½mv² to v = √2gh. This shows that if height changes by 2, velocity will change by √2.
How many hydrogen peaks (excluding bond-neighbor effects) would the molecule 3-ethyl-2-methylpentane show in its H-NMR? A. 5 B. 6 C. 8 D. 18
A. We can start with the hydrogens on the 1-carbon. We see that these hydrogens are all equivalent, are equivalent to the hydrogens on the 2-methyl group, thus this constitutes one peak. Then another peak from the hydrogen on the 2-carbon. Then an additional one from the 3-carbon. Then we see equivalent hydrogens on the 4-carbon and the 1-carbon of the ethyl group. Finally all of the hydrogens are equivalent on the 5-carbon and the 2-carbon of the ethyl group. Thus a total of 5 peaks in an H-NMR.
If blood pressure doubled and the resistance to blood flow increased by 50%, the amount of blood pumped by the hear would have (P = CO x VR, p: bp, CO: cardiac output, VR: vascular resistance) A. increased by 1/3 B. increased by 1/2 C. decreased by 1/3 D. decreased by 1/2
A. CO = P/VR. CO = 2P/(3/2)VR = 4/3, a 1/3 increases from 3/3
The reaction quotient (Q) is measured for a reaction, and it is found that Q < Keq. How will the reaction proceed? A) The reaction is at equilibrium B) The reaction will proceed towards the products C) The reaction will proceed towards the reactants D) The reaction is stable enough to stop
B) The reaction will proceed towards the products The reaction quotient is a measurement of the reactant and product concentrations at any point in a reaction, not necessarily at equilibrium. Q is defined as the concentrations of the products multiplied together divided by the concentrations of the reactants multiplied together. If Q is less than Keq (the equilibrium constant), there are less products than reactants. As a result, the reaction will move forward towards the products.
Which of the following proteins is most likely upregulated in liver cells when compared to heart cells? A) Tropomyosin B) Actin C) Fructose 1,6-bisphosphatase D) vSNARE
C) Fructose 1,6-bisphosphatase Liver cells carry out gluconeogenesis (heart cells do not), and fructose 1,6-bisphosphatase is an important enzyme in the process (choice C is correct). The other enzymes are likely similarly expressed in the cells (choices A, B, and D are incorrect).
Which of the following functional groups does NOT contain a carbonyl group? A) Aldehyde B) Amide C) Imine D) Carboxylic acid
C) Imine An imine contains a nitrogen double-bonded to a carbon whereas a carbonyl group contains an oxygen double-bounded to a carbon (choice C is correct). Aldehydes, amides, and carboxylic acids all contain carbonyl groups (choices A, B, and D are incorrect).
Tumor cells are shown to be able to survive in hypoxic conditions. What is most likely the terminal electron acceptor in metabolism during hypoxia? A) Oxygen B) Water C) Pyruvate D) ATP
C) Pyruvate In hypoxia, cells must use anaerobic respiration as oxygen can no longer serve as the terminal electron acceptor in the electron transport chain (choice A is incorrect). In anaerobic conditions, pyruvate is the terminal electron acceptor (choice C is correct). Water or ATP do not commonly serve as electron acceptors (choices B and D are incorrect).
A researcher discovers a new kinase inhibitor made of a glycerol backbone and three saturated fatty acid tails. Which of the following describes the path by which the inhibitor enters the cells? A) The inhibitor is recognized by a specific receptor. B) The inhibitor is taken up by a non-specific receptor. C) The inhibitor diffuses through the cell membrane. D) The inhibitor passes through the cell membrane via a channel.
C) The inhibitor diffuses through the cell membrane. The inhibitor described in the question stem is very hydrophobic, and this means it will pass through the membrane via diffusion (choice C is correct; choices A, B, and D are incorrect).
Pyruvate decarboxylase acts on pyruvic acid to produce: A. 2-oxopropanal and water/ B. propanone and water. C. acetaldehyde and carbon dioxide. D. acetic acid and carbon dioxide.
C. A decarboxylase enzyme will decarbozylate (remove a carboxy group, releasing carbon dioxide), so choices A and B can be eliminated. Once the carboxyl group is removed from pyruvic acid and replaced with a proton, the product is ethanal, also known as acetaldehyde.
Which of the following alkenes is the most stable? A. Ethylene B. Prop-1-ene C. 2,3 methyl but-2-ene D. Trans but-2-ene
C. All of the above structures have a double bond. The most substituted alkene is most stable because the negative charge that results from the removal of a proton would be stabilized by substitute groups. Thus, 2,3 methyl but-2-ene is the most stable since it has four substituted groups surrounding the two pi-carbons.
A woman carries an X-linked dominant gene on one of her X-chromosomes called DISe1 which gives her a particular phenotype. If she, theoretically, were to have 100 children, how many would be expected to have a matching phenotype? A. 100 children B. 50 boys, 25 girls C. 25 boys, 25 girls D. 25 boys, 0 girls
C. The gene is X-linked dominant, meaning that if a child inherits the X-chromosome with DISe1, they will have the phenotype. For each child, there is a 50/50 chance that they will get the X-chromosome with the gene mutation, regardless of child\'s gender. Thus, 25 boys and 25 girls would be expected to inherit the gene and have the phenotype.
Which of the following conditions would most likely lead to denaturation of the enzyme DNA polymerase? A. Temperature of 37°C B. pH of 7.0 C. [NaCl] = 300 mM D. Presence of Mg²⁺ and Mn²⁺
C. The main conditions that affect enzyme activity are enzyme/substrate concentrations, inhibitors, temperature, pH, and salinity. All of the above choices are necessary or wouldn't change rate except for an excessively high salt concentration. 300 mM would dissociate into 300 mM of each Na⁺ and Cl⁻, which are twice the normal levels.
A blood sample is withdrawn from a patient and spun down to remove the blood cells. The plasma is extracted and placed under a neutral atmosphere, and the oxygen gas is selectively removed. Which of the following would be expected of the pH of the plasma sample? A. the pH would rise B. the pH would drop C. the pH would be unaffected D. The answer cannot be determined with the given information.
C. The plasma lacks cells and would lack cellular metabolism and gas exchange mechanisms, meaning the presence of oxygen would not directly affect the CO2 concentration. Since O2 does not change the pH of a solution when dissolved, it would not be affected by the procedure mentioned in the prompt.
During glycolysis, energy is extracted in the form of what? A. CO2 B. Pyruvate C. Protons D. NADH and ATP
D. Glycolysis, taking place in the cytoplasm, breaks down glucose into two pyruvate molecules, which yields a net amount of 2 ATP and 2 NADH. The next process (the Citric Acid Cycle) uses pyruvate as a starting material to break down and yield more ATP and NADH, as well as FADH2.
An organism is discovered which lives in very cold environments close to 0 °C. Compared to organisms that live at room temperature, this cold-tolerant organism can be expected to: A. require more calories for survival. B. require thermostable enzymes for maintenance of metabolic pathways. C. have a high metabolic rate. D. have a high solute content in its cytosol.
D. It's not clear whether a cold-tolerant organism would require more calories to survive or whether it would simply have a slower metabolism; the relationship can't be inferred from the given information. (B) is incorrect as this is a characteristic of organisms living in high temperatures, not low temperatures. Low temperatures generally do not affect enzyme stability in any meaningful way. (C) is incorrect for similar reasons as answer (A); generally organisms living at lower temperatures have slower basal metabolic rates due to the decreased rates of reactions. (D) is the correct answer as low temperatures risk freezing, so organisms at these temperatures can be expected to maintain higher solute contents which will depress the freezing point and prevent their cells from freezing.
delta g equals
Delta H - T(Delta S)
When concentrated urine is being produced, what kidney region will have the highest glomerular filtrate concentration?
Medullary portion of the collecting duct
According to Spreading activation theory, what types of memories are most likely to be associated?
Memories that are SEMANTICALLY or CATEGORICALLY related
Air travel pathway
Nare --> Nasal cavity --> Pharynx --> Larynx --> Trachea --> Bronchi --> Bronchioles --> Alveoli
at equilibrium, Q>k, Q<k, or Q = K
Q = K
Cysteine
R-configuration, hydrophilic
How are proteins able to be removed from blood, yet not found in urine?
They can be destroyed (lysosomes) or packaged into something else (golgi apparatus)
Stem cells
Totipotent (all types), Pluripotent (germ layer), Multipotent (specific)
tropic vs direct hormones
Tropic: FSH, LH, ACTH, TH (mitochondria) Direct: Prolactin, Endorphins, GH (↑ protein synthesis & promote fatty acid breakdown)
T or F? RNAase contains peptide bonds and is degraded non-specifically in strong acid conditions
True!
Which fatty acids use isomerase & reductase during cleavage
Unsaturated (double bonds, reduction=trans)
What allows for intracellular protein transport to the plasma membrane in bacteria
active transport along cytoskeletal filaments (they dont have vesicles)
gamma decay
an excited nucleus gets rids of the extra energy by emitting a gamma ray - there is no change in the atom except the amount of energy in the nucleus is reduced
What would not interfere with the repeated transmission of an impulse at the neuromuscular junction
an increase in acetylcholine receptor sites at the motor end plate
In horses, the genes for red coat color and for white coat color are codominant. Heterozygous horses have roan-colored coats. Consider a roan-colored colt that has a white mother. What could be said about the coat color of the colt's father? A. it must be red B. it must be roan C. it could be either red or roan D. it could be either red or white
c. heterozygous are roan colored. Either a heterozygout or a homozygout dominant could pass the roan allele onto the offspring
big nucleolus is a characteristic of
cancer cells because they are replicating and have high metabolic activity
resistors in parallel does the exact same thing as
capasitors in series and resistors in series does the same thing as capacitors in parallel
what is stronger the carbon oxygen double bond or the carbon carbon double bond
carbon oxygen so a keto form of something always dominates over an enol form of something
When viewing an X ray of the bones of a leg, a doctor can tell if the patient is a growing child because the X ray shows: A. cartilaginous areas in the long bones B. bone cells that are actively growing C. the presence of haversian cells D. shorter than average bones
cartilaginous areas in the long bones Long bones grow via endochondral ossification, which requires cartilaginous growth plates at the ends of long bones, that thicken as cartilage and later become ossified.
how does the ligase join fragments?
catalyzing the formation of a covalent bond (phosphodiester bond) between adjacent nucleotides
if we decrease the magnetic field, what happens to the energy difference between a and beta?
energy decreases .˙. frequency decreases
Reversible reaction
energy minimized, entropy maximized, [ ] constant
Symbolic Interactionism
examines social interactions & focuses on how shared meaning is established
just list the 3 structures of hormones
examples of each + 1- PROTEINS = secondary messenger
allowing solute solvent interactions occur to form a solution is endo or exothermic
exothermic
Generalizability
external validity can it be replicated OUTSIDE the lab
during ejaculation, what happens to the vas deferense, epididymis, and accessory glands?
filled with norepi = vasoconstrict = push semen out
why does chlorine have a higher electron affinity than fluorine?
fluorine has a small radius .˙. more repulsion between electrons and is harder to add that electron
E = E˚ - (RT/nF) lnQ
for 25 degrees, log form: E = E˚ - (0.0592V/n) * logQ
2nd law of thermo
for a spontaneous process a delta S for the UNIVERSE is greater than zero
work = ?
force x distance
sucrose structure
glucose + fructose
Resistivity
inverse of conductivity
oxidation
loss of electrons increased oxidation state
basic amino acids
lysine, arginine, histidine
high sexual dimorphism
males females are looking different
Cholera disease
massive diarrhea and vomiting death due to dehydration
(heat equation)q=
mc(delta T) (mcat) (this is to heat things without phase change c= specific heat) (heat of fusion (melting) is q= mL where L is heat of fusion #)
to find the resistance of something
measure the current running through the resistor with a known voltage V = IR
gametes are the end product of
meiosis and are haploid which go on to fuse with the other parents haploid gametes to make a diploid organism
Which of the following organelles plays a key role in apoptosis (programmed cell death)? Please choose from one of the following options. endoplasmic reticulum mitochondrion lysozome golgi apparatus
mitochondria Programmed cell death initiates with the degradation of organelles that are essential for cellular processes The mitochondria of a cell are perhaps the most essential for the immediate life of the cell, as this is where the energy to power enzymes and maintain ion gradients comes from Degradation of the mitochondria plays a key role in apoptosis
Heteroplasmy
mitochondrial self replication & cell division --> variability of mitochondrial composition
Torque =
moment arm * F * sin(theta)
if substance x is more easily oxidized than substance y, we say that substance x is_____(more/less active?)
more ACTIVE than y
In cellular respiration, which step causes the difference in ATP yield occur between prokaryotes and eukaryotes and by how many ATP?
occurs in the ETC, by 2 ATP (prok. has more)
Cultural transmission
one generation passes culture to the next
How many electrons can cytochrome c carry?
only 1
How many electrons cane heme carry?
only 1 b/c they cycle between ferrous and ferric states
D vs L amino acids
only L amino acids synthesize proteins
traditional behaviorism
only actual outcomes of behavior determine whether behavior will be accepted
limits of the voltage are controlled
only by the battery
Muscle fiber subtype 1
slow oxidative
Stability of cyclic molecules
small rings (less than 5 carbons): ↓ stable, ↓ keq big rings (more than 5 carbons): ↑ stable, ↑ keq
meritocracy
society where leaders are chosen because they are most skilled
Is H202 always an oxidizing agent
usually but NOT ALWAYS; you have to look at the reaction itself
If you increase the pressure of water at constant temp, what phase changes will you observe
vapor --> solid --> liquid
Venturi effect
velocity ↑ (maintain continuity) as hydrostatic pressure ↓ (conserve mech energy)
what stretches infinitely viscous component or elastic
viscous
high Km = [strong/weak] binding of substrate .˙. [product/substrate] is favored
weak binding = substrate favoured
Hypothalamus
what hormones it makes and their function + - "control center" in the forebrain region of the brain - stimulates pituitary gland - makes ADH + oxytocin * ADH: anti-diaretic hormone which regulates fluid levels * oxytocin: stimulates uterus contraction
what 4 things can cause a protein to denature?
what structures does it denature? + - temp: 2,3,4 - pH: disrupts ionic bonds (3,4) - chemicals: denatures H-bonds .˙. 2,3,4 - enzymes: 1˚
2 components of the pancreas
what they secrete + 1- exocrine pancreas: release salts + enzymes into duodenum 2- endocrine pancreas: releases hormones into blood stream
secondary structure
what type of bond + Either an alpha helix or beta pleated sheet, H-bond between amide groups of different AA
primary structure of protein
what type of bond + amino acid sequence itself, peptide bond
difference in cardiac output formula
(systolic pressure-diastolic)/resistance = cardiac output
what are the 3 enzymes that catalyze lipid membrane movements?
- bc catalyzed, this action is FAST 1- flippase: uses ATP; brings something from the outer leaflet to the INSIDE leaflet 2- floppase: uses ATP; inside goes outside 3- scramblase: doesn't require ATP; switches something from the inside leaflet to outside and vice versa
what are the functions of cerebrospinal fluid?
- electrolyte balance - protection of the brain - reduction of brain ischemia (bc in cases of ischemia, the CSF decreases to decrease pressure in the brain and allow the heart to pump more effectively to the brain and perfuse it )
uncompetitive inhibition? how are Km and Vmax affected?
- inhibitor binds ONLY to enzyme-substrate complex - locks substrate in enzyme preventing its release (increasing affinity b/w enzyme and substrate so it lowers Km) - Lower Km and vmax
What are the 7 major endocrine glands?
- major major 2: hypothalamus, pituitary - remaining 5: thyroid, parathyroid, pancreas, gonads, adrenal gland (cortex + medulla)
whats competitive inhibition? how are Km and Vmax affected?
- molecules COMPETE with the substrate for enzyme's active sites - can be overcome by adding more substrate - vmax not affected, Km increases
Types of Immunity
-Active: vaccine, adaptive memory cells -Passive: admin of exogenous antibodies -Innate (nonspecific): NO immune memory -Adaptive (specific): immune memory, B/T cells -Humoral: Activated antigen (hypermutation), Circ. antigen (opsonize & agglutinate), cell-surface antibody (mediate allergic rxn), memory B-cell -Cell-mediated: Helper (CD4-MHC II for antigen cells & exogenous antigen). Cytotoxic (CD8-MHC I for nucleated cells & endogenous antigen), Suppressor (↓ immune resp), Memory T-cell.
meters
-Ammeter: series, current, neglig resistance -Voltmeter: parallel, voltage drop, large resistance -Ohmeter: resistive element, resistance, neglig resistance
Explicit memory (conscious)
-Episodic: events/experiences -Semantic: facts/concepts
Neuron segments
-PCT: Reabsorb protein, glucose, amino acids -Descending loop: Concentrated. H2O -Ascending loop: Diluted. Salt -DCT: adjust [ ] of urine before excretion. Aldosterone -Collecting duct: Aldosterone/ADH. Vasopressin
coding strand
-mRNA is always a REPLICA of DNA strand (includes U instead of T)
Piaget's stages of cognitive development
-sensorimotor (object perm) AGES 0-1 -pre-op (ego, symbols) AGES 2-7 -concrete op (feeling of others) AGES 8-11 -formal op (abstract thought) AGES 12+
how many NADHs are needed to reduce a protein
1 NADH per disulfide bond
1 atm in torr, mmhg, kpa,
1 atm = 760 torr = 760 mmHg = 101.3 kPa
Conversion between faradays and moles of electric charge
1 faraday = 1 mol of electric charge
steps of oogenesis
1- During first 7 months, the germ cell (oogonia) goes under millions of divisions (mitosis) 2- At 7 months, the oogonia matures into a PRIMARY OOCYTE 3- Primary oocyte go through 50% of meiosis 1 and then goes under "meiotic arrest" 4- Around 13 years later is when it finishes meiosis 1 and becomes a secondary oocyte *meiosis 2 occurs when the egg is fertilized
the 3 functions of the stomach:
1- churns the bolus received from the esophagus and turns it into chyme 2- enzyme assisted breakdown of food 3-stores food
Erikson Development (internal conflicts)
1. Trust and mistrust (0-1) 2. Autonomy and shame/doubt (1-3) 3. Initiative and guilt (3-6) 4. Industry inferiority (6-12) 5. Identity and role confusion (adolescents) 6. Intimacy and isolation (young adults) 7. Generativity and stagnation (middle age) 8. Integrity and despair (elderly)
How many reduced electron carriers are generated during conversion of alpha ketoglutarate to oxaloacetate during the TCA cycle
3 (2 NADH, 1 FADH2)
Which of the following is NOT a carboxylic acid derivative? A) Alcohol B) Ester C) Amide D) Thioester
A) Alcohol An alcohol contains an -OH group, but it does not have a carbonyl (C=O) group (choice A is correct). Esters, amides, and thioesters are all carboxylic acid derivatives (choices B, C, and D are incorrect).
If positive ions are surrounded by a sea of mobile electrons, electrons oscillate through equilibrium to point the next crest of the wave because: A. the momentum gathered as they move from the first crest B. coulomb forces pulling on the electron sea C. magnetic forces of attraction between the positive ions and the electron sea D. the large potential energy they have at the second crest
A. As the electrons move from the first crest to equilibrium, they convert potential energy into kinetic energy and gain velocity and momentum as they do so. Kinetic energy reconverts to potential energy when the electrons move to the second crest
What is the best explanation for the fact that a solution of NaNO2 is basic? A. NO2- is hydrolyzed with the formation of OH- ions B. Na+ is hydrolyzed with the formation of OH- C. NaNO2 decreases the Ka of HNO2 D. NaNO2 increases the Ka of HNO2
A. The NO2- reacts with water, forming OH- ions.
How does vapor pressure affect evaporation rate? A. the greater the vapor pressure, the greater the rate of evaporation B. the smaller the vapor pressure, the greater the rate of evaporation C. vapor pressure is inversely related to rate of evaporation D. vapor pressure and rate of evaporation are unrelated
A. The greater the vapor pressure, the greater the rate of evaporation.
Would an increase in the level of plasma aldosterone be expected to follow the ingestion of excessive quantities of NaCl? A. no; aldosterone causes Na+ reabsorption by the kidney tubules B. no; aldosterone causes Na+ secretion by kidney tubules C. yes; aldosterone causes Na+ reabsorption by kidney tubules D. yes; aldosterone causes Na+ secretion by kidney tubules
A. aldosterone (produced by adrenal cortex) causes Na+ reabsorption by kidney tubules thus and increase in plasma aldosterone would not be expected because the body would not want to retain more salt
If a student did NOT remove all the moisture from the KHP before the titration with NaOH, then the molarity determined for the NaoH would be: A too high because the actual number of moles of KHP titrated would be less that the number used in the calculations B. too low because the actual number of moles of KHP titrated would be more than the number used in the calculations C. too low because the actual number o moles of KHP titrated would be less than the number used in the calculations D. unaffected because the weighed KHP was dissolved in water
A. in the titration of KHP and NaOH, the number of moles of KHP titrated equals the number of moles of NaOH needed to reach the equivalence point. if a student weighs a sample of KHP and water the mass will be larger than the mass of KHP alone
In a nearsighted individual, the image of a distant object is focused: A. in front of the retina, requiring divergent lens correction B. in fron of the retina, requiring convergent lens correction C. behind the retina, requiring divergent lens correction D. behind the retina, requiring convergent lens correction
A. nearsighted (myopic) people focus nearby objects correctly but cannot focus distant objects
Types of systems
Adiabatic: no heat exchange ΔQ=-W Isobaric: constant pressure Isochoric: constant volume ΔU=Q Isothermal: constant temp Q=W
If an enzyme has normal Vmax in vitro but much higher in vivo, what does this tell you about the site of the mutation
Allosteric site, can't be bound by allosteric inhibitors
Interoceptive awareness involves sensitivity to increases in the activity of the
Autonomic Nervous System
Cells are treated with a drug that dissipates the proton gradient across the inner mitochondrial membrane. What is the net result? A) Cancer progression is halted B) ATP cannot be produced via ATP synthase C) The cell will use exocytosis to dispose of the nonfunctional mitochondria D) Cells will rapidly evolve a new ATP synthesis mechanism
B) ATP cannot be produced via ATP synthase The proton gradient is generated so that protons flow from the intermembrane space into the matrix based on their chemical gradient. The passage of protons through the inner mitochondrial membrane then allows ATP synthase the necessary energy to produce ATP. The question stem does not address cancer progression (choice A is incorrect). The cells will not get rid of the mitochondria when they stop working, and they are also unlikely to rapidly evolve a new ATP synthesis mechanism as the first one likely took millions of years to develop in the first place (choices C and D are incorrect).
Which of the following describes the process by which fatty acids are broken down for use as energy? A) Glycolysis B) Beta oxidation C) Beta reduction D) Gluconeogenesis
B) Beta oxidation Fatty acids are broken down via beta oxidation (choice B is correct). Glycolysis describes the breakdown of glucose (choice A is incorrect). Beta reduction is not a commonly used term in metabolism (choice C is incorrect). Gluconeogenesis describes the biosynthesis of glucose (choice D is incorrect).
Which of the following best characterizes Malthusian theory? A) Humans will run out of useable water. B) The human population will exceed the food supply. C) Globalization will alleviate concerns about food supply shortages. D) Subsistence farming will produce sustainable change in the future.
B) The human population will exceed the food supply. Malthusian theory was a prediction stating that the exponential growth of the human population would exceed the food supply (choice B is correct; choices A, C, and D are incorrect).
Which of the following pairs of elements would have the most reactive reaction? A. C and H B. Cs and Cl C. Ba and S D. B and H
B. The reactivity of a reaction increases as the difference in size and electronegativity increases. This is because a reaction is more reactive when there is a more likely exchange of elections. Since Cs and Cl are the furthest from each other of the given pairs, they will have the strongest reaction.
Which of the following has the largest total cross-sectional area? A. Aorta B. Capillaries C. Arterioles D. Small Veins
B. We are looking at total cross sectional area, i.e. the sum of all of the cross sections of each of the vessels. The capillaries actually have the largest total cross-sectional area because there are significantly more capillaries than any other vessel. This makes sense because capillaries allow for exchange between the blood and tissues within the body, thus it would be optimal to have large cross-sectional area of capillaries to allow for efficient exchange of nutrients and gases.
Which of the following correctly lists the ions in order from smallest to largest? A. S²⁻, Cl⁻, Ca²⁺, K⁺ B. Ca²⁺, K⁺, Cl⁻, S²⁻ C. Cl⁻, S²⁻, Ca²⁺, K⁺ D. S²⁻, Cl⁻, K⁺, Ca²⁺
B. What each of the ions listed have in common is that they have the same number of electrons. Therefore, the smallest ions will have the most protons, because the protons will pull the electrons closer to the nucleus. Similarly, the largest ions will have the fewest protons. Therefore, the smallest ion will be Ca²⁺ because it has the largest atomic number and thus has the most protons. Similarly, S²⁻ has the fewest protons and is thus the largest of the ions. The answer directly follows.
Which of the following will occur if the acidity of a saturated solution of Ca(OH)2 is increased? A. the Ksp will decrease and additional Ca(OH)2 will dissolve B. the Ksp will be unchanged and additional Ca(OH)2 will dissolve C. the Ksp will decrease and additional Ca(OH)2 will precipitate. D. the Ksp will be unchanges and additional Ca(OH)2 will precipitate
B. The only thing that can affect Ksp is temperature. If the acidity of the solution in increased, the added acid will react with the hydroxide ions produce allowing more OH ions to dissolve.
If ocean waves strike the shore every 3.0s and the horizontal distance between adjacent crests and troughs is 1.0 m, what is the average speed of the waves? A. 0.33 m/s B. 0.67 m/s C. 1.5 m/s D. 3.0 m/s
B. v = λF. Frequency = 1/3 seconds and wavelength = 2 x 1 because a crest an adjacent trough are a half wavelength apart. v = 2 x 1/3 = .67 m/s
A mouse in Group 3 is given 50 mg of oxaliplatin. If the half-life of the drug is 6 hours, how much will remain in the mouse at 24 hours? A) 12.50 mg B) 6.250 mg C) 3.125 mg D) 1.562 mg
C) 3.125 mg After 6 hours, 25 mg remain. After 12 hours, 12.5 mg remain (25/2). After 18 hours, 6.250 mg remain (12.5/2). After 24 hours, 3.125 mg remain (6.250/2)
Which of the following is NOT a strong acid? A) Hydrochloric acid B) Sulfuric acid C) Acetic acid D) Hydrobromic acid
C) Acetic acid Acetic acid is a weak acid, meaning its proton dissociates weakly in solution (choice C is correct). Hydrochloric acid, sulfuric acid, and hydrobromic acid are strong acids (choices A, B, and D are incorrect).
Which of the following amino acids would most strongly interact with an active site containing histidine? A. R B. K C. D D. V
C. A positively charged active site would most likely interact with aspartic acid, which is negatively charged. (A) and (B) are incorrect since these amino acids are also positively charged, and (D) is incorrect since valine is nonpolar.
What is the net charge on the R-groups of the following five amino acids at pH 7.4? (alanine, threonine, glycine, asparagine, and tyrosine) A. -2 B. -1 C. 0 D. 1
C. The basic amino acids - which are positively charged at pH 7.4 - are arginine and lysine. The acidic amino acids are aspartic acid and glutamic acid. Since none of these amino acids appear, the net charge on those five amino acids should be zero, which is choice C.
How do carbs, amino acids, & fats enter circulatory system?
Carbs/amino acids: hepatic portal system of small intestine Fats: Thoracic duct of small intestine
would you expect CH4 or ClCH3 to have a greater chemical shift? explain
ClCH3 would have a greater chemical shift; since chlorine is much more electronegative than carbon, the electrons will be pulled towards it .˙. making the protons deshielded = higher magnetic field energy = higher frequency = higher chemical shift
Cohesion vs. Adhesion
Cohesion = attraction of particles for each other Adhesion = attraction of particles for a surface
Vasopressin regulates the insertion of aquaporins into the apical membranes of the epithelial cells of which renal structures
Collecting duct
Types of bonds
Covalent: nonpolar (EN = 0-0.5) & polar (EN = 0.5-1.7), coordinate (single atom provides most e-) Ionic: EN = 1.7+ . ↑ melting point
At which carbon do cyclic hemiacetals and acetals differ in alpha and beta orientation?
Cyclic hemiacetals and acetals differ in alpha or beta orientation at the carbon atom that bears two oxygen substituents
Given the same wire resistance and length of a metal tube, which of the following cross-sectional areas would provide the greatest resistivity? A) 1 m2 B) 10 m2 C) 25 m2 D) 100 m2
D) 100 m2 Resistivity is equal to resistance times cross-sectional area divided by length. So, cross-sectional area is directly proportional to resistivity, meaning answer choice D is correct since it has the greatest cross-sectional area.
The rate at which a reaction proceeds is given by the following equation: rate = k[A]2[B]. What order is the overall reaction? A) Zero order B) First order C) Second order D) Third order
D) Third order The exponent for [A] is 2 and [B] is 1, so the total overall reaction order is 3 (choice D is correct; choices A, B, and C are incorrect). Rate laws are determined by the equation: rate = k[A]x[B]y
Bone tissue does NOT serve which of the following purposes in the human body? A. Blood cell production B. Sound transduction C. Mineral storage D. Heavy metal and toxin excretion
D. Bone marrow is responsible for blood cell production, making (A) incorrect. The malleus, incus, and stapes of the ear are responsible for transducing sound from the outer to the inner ear, making (B) incorrect. Bone tissue stores minerals like calcium and phosphorus, making (C) incorrect. Heavy metals can be sequestered and stored in the bone, but this does not serve as an excretion process. The stored metals must still be released for excretion from the body, making (D) the correct answer.
TABLES/GRAPHS
DO NOT indicate any statistical significance
Where would additional synapses be placed in the reflex pathway to incorporate a sensation of pain
DRG and VRG. (Synapses at the painful stimulus and muscle effector are already part of the pathway)
Myoglobin in the urine indicates what
Damaged muscle or damaged organs myoglobin holds oxygen in both muscle and organs
Pulmonary edema occurs when fluid builds up in the interstitium between the pulmonary capillaries and the alveoli, and eventually enters the alveoli. How do you decrease the risk of pulmonary edema? A. Decrease hydrostatic pressure and increase osmotic pressure B. Decrease hydrostatic pressure and decrease osmotic pressure C. Increase hydrostatic pressure and decrease osmotic pressure D. Increase hydrostatic pressure and increase osmotic pressure
Decrease hydrostatic pressure and increase osmotic pressure Hydrostatic pressure is the pressure a liquid exerts on its container, and reflects the volume of liquid in a space. Osmotic pressure is the pressure required to prevent movement across a semipermeable membrane, and reflects the protein content of the blood. To decrease the risk of pulmonary edema, hydrostatic pressure exerted by the fluid must decrease, and osmotic pressure exerted on the fluid must increase.
How to add/lower pH
Decrease: increase acidic buffer Increase: increase basic buffer
Drug classes
Depressants: ↑ GABA (stabilizer) Stimulants: ↑ Dopamine (glucose), norepinephrine, serotonin Opiates: Hallucinogens: lowest risk of dependence
Fever in septic shock leads to which of the following compensation mechanisms? A. Dilation of capillary beds in the skin B. Increased skeletal muscle activity C. Decreased respiration rate D. Decreased fluid loss
Dilation of capillary beds in the skin To compensate for the increased body temperature in a fever, skin capillaries dilate to dissipate heat throughout the skin.
What is the advantage of the Doppler ultrasound technique over the standard ultrasound technique?
Doppler ultrasound also allows you to measure blood flow b/c blood changes frequency when moving inside a blood vessel.
What are the 4 types of human interaction approaches?
Dramaturgical: self-image changes based on environment Freudian: subconscious, internal state Residual: self-image changes based on net income Developmental: self image changes based on age
What phenomenon likely causes hyperpolarization? Excessive influx of K+ Excessive influx of Na+ Excessive outflow of K+ Excessive outflow of Na+
During an action potential, Na+ flows in and K+ flows out. Thus, choices (A) and (D) may be eliminated. More specifically, Na+ first flows in down its electrochemical gradient to depolarize the cell membrane. K+ flows out down its electrochemical gradient to repolarize the cell. It is when this outflow is excessive that the membrane becomes hyperpolarized. Thus, choice (C) is the correct answer.
Succinyl coA synthetase
Enzyme that catalyzes conversion of Succinyl CoA to Succinate + GTP
A 23-year old female reports experiencing severe bloating and water retention at certain points during her menstrual cycle. Which hormone associated with the regulation of salt and water retention could be causing her problem? Estrogen Prolactin Cortisol Progesterone
Estrogen Prolactin is associated with milk production during pregnancy. Progesterone does not play a major role in fluid balance. Estrogen has a major role in fluid balance and could be linked to bloating and water retention during the menstrual cycle.
menopause
Estrogen/Prog ↓ FSH/LH ↑
Incentive theory is most closely aligned with what sociological framework
Exchange theory
What most influences NT release: receptor sensitivity, receptor density, or extracellular Ca2+?
Extracellular Ca2+ b/c Ca2+ channels open and Ca2+ influx is necessary for Ca2+ flow into the terminal -->vesicle formation --> vesicle release
gravitational force equation, what do the constants stand for?
Force gravity = G * mM/r^2 G = constant m = mass of object M = mass of planet r = radius of planet
esterification reaction
Formation of esters from carboxylic acids and alcohols, in the presence of an acid - the H from the alcohol group is lost, and the OH from the COOH is lost .˙. water is released and an ester forms
Retina
Fovea: more cones (daytime) Periphery: more rods (photosensitive, dim light)
What happens when Quinone is reduced to Hydroquinone?
Gains 2 electrons & 2 protons
heterochromatin vs. euchromatin
HeteroChromatin = Highly Condensed (transcriptionally inactive) euchromatin = less condensed, transcriptionally active ("truly transcribed")
A medical student's sense of self-efficacy and confidence in patient interactions is most likely to manifest via what phenomenon?
Impression Management
unconditioned response (UR)
In classical conditioning, the unlearned, naturally occurring response to the unconditioned stimulus (US), such as salivation when food is in the mouth.
Increasing the frequency of each photon directed at the cathode will
Increase the speed of the ejected electrons (photon energy equals cathode work function + electron KE). The number of ejected electrons depends on the # of incident photons, not the frequency of each photon.
What phenomenon would a rabbit trainer most want to avoid when training a rabbit for a commercial
Instinctual drift
Pancreas hormones
Insulin (beta cells): anabolic, reduce blood sugar Glucagon (alpha cells): catabolic, ↑ blood sugar Somatostatin (delta cells): inhibit insulin/glucagon
L vs D amino acids
L: amine group on the Left on fischerman projection D: amino group on the right
Branched amino acids
LEU, ISO, VAL
Basic amino acids (+ charged)
LY, ARG, HIS (heterocyclic imid ring)
Linguistic relativity
Language affects speakers' perceptions
Which is more likely to be localized to the left hemisphere? Music perception or vocab skills
Language skills
Ka
Large: ↑ dissociation at ↑ temp -Reaction requires heat (endothermic) -Enthalpy: H > 0 -The ↓ the pKa, the ↑ the Ka
Dipole
Least electronegative = LEAST dipole moment
Which 2 factors are required for detection of stimulus?
Length & physiological state
How does the myogenic response (the response that regulates blood vessel diameter in response to pressure) respond to SNS stimulation in the brain
Moderates blood flow to the brain under high pressure
Upper right periodic trend
More Electro neg/ Ionization Energy/ Electron affinity
Neurons
Motor: CNS ventral --> Effector (efferent) Sensory: sensory --> CNS dorsal (afferent)
What mitotic process would a drug that prevents microtubule formation stop?
Movement of chromosomes to opposite poles during anaphase
If delta GTPrxn = 0, is ATP produced or consumed
NO! It's neither produced nor consumed
can 2 eggs be fertilized by a single sperm?
NO, 2 eggs cannot be fertilized by a single sperm
Of the following tissues, which is NOT derived from embryonic mesoderm? A. Circulatory B. Bone C. Nerve D. Dermal
Nerve Nervous tissue comes form ectoderm
Do people with Alzheimer's have proactive interference?
No because proactive interference requires information previously stored in long term memory which can impede the learning of new info
CO₂ dissolves in water. Once dissolved, A. It decreases the pH of the solution due to formation of HCO₂
OH⁻ B. It decreases the pH of the solution due to formation of HCO₃ + H⁺ C. It increases the pH of the solution due to formation of HCO₂ + OH⁻ D. It increases the pH of the solution due to formation of HCO₃ + H⁺ + B. When CO₂ dissolves in water, it forms carbonic acid; H₂CO₃ by reacting with the water. H₂CO₃ then dissociates into H⁺ and HCO₃.
Which participant in the electron transport chain has the greatest attraction for electrons? A. FAD B. NAD+ C. Oxygen D. Cytochrome c
Oxygen The final electron acceptor, Oxygen, has the greatest attraction for electrons
The following elementary reaction was performed: NO
O₃ ↔ NO₂ + O₂. Which of the following correctly describes the rate equation? kf represents for the forward rate, while kr is for the reverse reaction. A. Rate = kf[NO]²[O₃] B. Rate = kr[NO₂][O₂] C. Rate = kf[NO][O₃][NO₂][O₂] D. Rate = kr[NO][O₃] + B. Note the subscripts of the rate constant k. The rate can either be written as kf[NO][O₃] given the forward reaction or as kr[NO₂][O₂], because the rate can be determined by the reactants of the forward reaction or the reactants of the reverse reaction.
Power at constant speed
P = Fv
Neighborhood level social inequalities most likely affect physician-patient interactions through which phenomenon?
Physical boundaries create social boundaries and closed networks which generate their own cultures
1st law of thermo is = internal energy =
Q - W
Social
Reproduction: disparity passed through generations Privilege: inequality between diff groups Capital: personal benefits from prof. socialization Meritocracy: testing/IQ
Native gel electrophoresis
Runs protein in its native state, doesn't reduce proteins to monomers or disulfide linkages
What would support the validity of a measure
Same result on a different measurement method
Mucous Cells (Stomach)
Secrete mucin (mucous) which lines the stomach walls and prevents the stomach from eating itself
Why would a cell be growth-arrested as an experimental control?
So that is does not interfere with measurement of the growth of the cell being measured (not necessarily to prevent inhibition of cell growth)
systole vs diastole
Systole: contract, AV valves close, Semilunar valves open, & ventricles contract to pump blood out of arteries Diastole: relax, all valves close, blood flows from atria --> ventricles
Chromatography
TLC (capillary action), Column (gravity), Gas (absorbance- lowest weight migrates fastest & shows first peak), HPLC
What does the serial position effect demonstrate about memory systems?
That STM and LTM are different systems
A 20 kg child sits on a swing with ropes 2 m long. The maximum speed during each swing is 4 m/s with an arc of 135°. What is the maximum tension in the swing? A. 160 N B. 200 N C. 360 N D. 240 N
The arc isn't relevant if we're given the maximum speed. Since the swing will move along the path of a circle, we can use the equation for centripetal force to calculate the maximum force. At the maximum speed, the force on the swing is due to the weight of the child plus the centripetal force. The weight of the child is mg = 200 N, while the centripetal force is F = ½mv² = ½(20)(4²) = 160 N. Thus the total maximum force on the swing is 360 N.
How do you know which side of the ribose is 3' and which side is 5'?
The side closest to the nucleotide is 5'
Treatment with an enhancer would provide most benefit to people with disorders of the enhancer itself or the system it targets?
The system it targets
_____ hormone passes through the cell membrane and the mitochondrial membrane to exert a portion of its influence on metabolism.
Thyroid Hormone
Translational vs Transcriptional regulation
Trans reg: translation of RNA --> protein (mRNA dormant) Transcrip reg: transcription of RNA from DNA
what is NOT a function of hair
Trap sweat and increase heat loss duh it cools the body
stop codons are
UAA, UGA, UAG
Prefrontal cortex
Ventral prefrontal: emotional experience Ventromedial: control emotion (amygdala) & decision
Vmax in terms of Kcat and E
Vmax = kcat [E]
How will the work done change if the angle of the ramp to the horizontal is increased?
Work will decrease because the normal force to the surface of the ramp will decrease
confounding variable
a factor other than the independent variable that might produce an effect in an experiment
What is the endocrine system?
a set of glands that produce hormones and cause an effect
alpha vs beta spin
alpha: the proton magnetic moment aligns with the external magnetic field beta: proton magnetic moment goes against the external magnetic field
don't have an oxygen a) amine b) ester c) nitrate d) nitrosyl
amine
what does a small Km mean? vs large
an enzyme only needs a small amount of substrate to be saturated, it takes a small amount of substrate to reach Vmax
spermatogonium cells
are the precursor of sperm
Hawthorne effect
change in subject's behavior caused by awareness of being studied
just noticeable difference
change/original
Mastication
chewing
3 types of cells in the stomach
chief, parietal, mucous
elaborative encoding
combining new info with existing memory which enhances probability of retrieving that new info
what is the bone marrow function?
contains stem cells used to make all types of blood cells
If a gene is only expressed in one gender, what chromosome is it on
could be on a sex chromosome or an autosome; you can't tell based on expression.
Nephron function
creates urine hypertonic to blood
How are peptide bonds formed?
dehydration synthesis or addition-elimination rxn
equilibrium
delta g equals 0 Delta G is negative means spontaneous
Buoyant force equation
fluid density * volume of object submerged * g
Lymphatic system functions
fluid, fat, immune response, B-cell antigen
Connexin
gap junction protein
beta- decay
has too many neutrons =====> top remains constant, atomic number (bottom) gains 1
what is specific gravity
how dense molecule x is compared to water
conditioned stimulus (CS)
in classical conditioning, an originally irrelevant stimulus that, after association with an unconditioned stimulus (US), comes to trigger a conditioned response.
in a parallell circuit with two resistors adding a third parallel resistor would do what to the current drawn from the battery
increase it
in a parallell circuit with two resistors removing resistor two would do what to the total resistance of the circuit
increase it
in a series circuit with 2 resistors adding a third resistor in series would do what to the total resistance of the circuit
increase it
what is a membrane protein that spans the whole 2 sides of the membrane called?
integral proteins
Surface tension is a measure of:
intermolecular forces
What is ischemia? what is hypoxia?
ischemia: inadequate blood supply to an organ or part of the body hypoxia: lack of oxygen to an organ
Which enzymes form NADH & CO2
isocitrate, alpha-ketoglut, & malate
closed systems vs isolated systems
isolated are no matter or heat or anything transfer closed system is only a no matter transfer system
removing capacitor 2 from a series circuit will do what to the circuit and capacitor 1
it will increase total capacitance of the circuit increase the charge drawn from the battery, increase the voltage drop across the remaining capacitor and increase the charge stored on capacitor 1
adrenal gland
its hormones + - on top of the kidney - has 2 parts: *CORTEX: outer part, makes steroid hormones: cortisol (stress hormone) + aldosterone (regulates blood levels) *MEDULLA: inner part, makes catecholamines: epi + norepi
Proteins that move along microtubules originate from where?
kinetochores
social cognitive theory
learning through vicarious learning, modeling, observation (↑ self-efficacy)
downfield vs. upfield NMR spectra
left = downfield right = upfield
phosphoester bond
linkage between the 5' sugar hydroxyl and a phosphate group
DNA ligase
links bases as last step of base repair after polymerase
anode =
low ph end of gel Anode Acidic
volume = ?
mass/density or area * distance
gram +
more peptidoglycan (dark purple) gram neg = outer membrane thin
adiabiotic
no heat change (q = 0)
Compounds with the formula AOm(OH)n are generally acids if A is a
nonmetal
For geometrical optics problems involving the human eye where do you assume image is located
normal-on retina myopia - in front of retina hyperopia behind retina
Which area of the brain would most directly be involved with 'image-forming vision'?
occipital lobes
sensory interaction
one sense may influence another (standing on one foot and keeping eyes open)
how does urine not backflow in the ureter?
one way valves
How is water absorbed?
passive transport using aquaporins
What is RNA interference (RNAi)?
posttranscriptional method of regulating gene expression - inhibition of gene expression by RNA molecules
how does methylation of DNA affect gene expression?
prevents the binding of transcription factors
Cytochromes
proteins involved in redox reactions.
procedural bias
refers to how information is obtained and may occur when researchers put some sort of pressure on subjects to provide responses.
Degree of assimilation
relative SES, geographic distrib, language attainment, intermarriage
the eye cannot get the focal length long enough then the ciliary muscle cannot
relax sufficiently
t tubule depolarization cases
sarco reticuclm to release CA 2+
compare the length and dissociation energy of single and double bonds
single bonds are longer and have lower dissociation energy
total work done on a graph that shows a shape in a P vs V plot is equal to
the area of that triangle
the more
the reduction potential for a specific substance, the more likely that a substance will be reduced/oxidized? + REDUCED!
life course perspective
the study of changes in individuals' lives over time, and how those changes are related to historical events
what is a reduction agent (RA)
the substance causing the OTHER substance to get reduced and itself getting OXIDIZED
fundamental attribution error
the tendency for observers, when analyzing another's behavior, to underestimate the impact of the situation and to overestimate the impact of personal disposition
social loafing
the tendency for people in a group to exert less effort when pooling their efforts toward attaining a common goal than when individually accountable
Hawthorne effect
the tendency for people to behave differently when they know they are being studied/watched
social desirability bias
the tendency for people to say what they believe is appropriate or acceptable
What is a brush border and where is it found?
the walls of the duodenum which is composed of villi + microvilli + villi enzymes
what are the 3 kinds of hormones?
their definition + - autocrine: function at the cell that produces them - paracrine: function regionally - endocrine: function @ a distance
adding a third capacitor in series to a circuit with 2 capacitors in series already will do what to the voltage drop across capacitor 1 and the charge stored on it
they both go down
how do strong acid and base conjugates affect pH?
they don't
Location of transcription vs translation in eukaryotes
transcription: nucleus translation: cytoplasm
Transferase
transfer functional groups, req ATP
What is the best method to prevent recurrence of stomach ulcers
use of drugs that inhibit acid production and bacterial protein synthesis
What gets reabsorbed in the descending loop of Henle
water only (passively), its impermeable to ions
behavioral
what causes behavior
Maladaptiveness
whether behavior negatively impacts persons life or poses threat to others
is 10% of a data sample a large number?
yes
relationship between ∆G and Q
ΔG= ΔG˙ +RT lnQ
Tautomers
- 2 isomers that differ with their location of a D-bond and most commonly an H atom
pI
-A LOW pI : amino acid is negative, acidic, and binds to anion-exchange. Req HIGH [ ] for elution -A HIGH pI: amino acid is positive, basic, and binds to cation-exchange. Requires LOW [ ] for elution
Pyruvate intermediates
-Acetyl-CoA: citric acid (PDH) -Lactate: fermentation (lactate dehydrogenase) -Oxaloacetate: gluconeogenesis (pyruvate carbox)
Km
-measures affinity of enzyme for substrate; defined as substrate concentration when an enzyme is functioning at half of its maximal velocity -can't be altered by changing concentration of substrate or enzyme low Km - high affinity of enzyme for substrate high Km - low affinity of enzyme for substrate
Pouseuille's Law
-resistance ↑, flow ↓ -Pr^4 / 8uL
2 thermodynamic eqs ∆G =
1) ∆G˚ = -RTlnK R = 8.314 2) ∆G = ∆G˚ + RTlnQ
4 functions of the liver
1- metabolism: anabolism + catabolism 2- storage of carbs + fats in the form of glycogen, lipoproteins, triglycerides 3- detoxification 4- Bile production
whats normal atmospheric pressure
101 kpa
What is the net volume of fresh air that enters the alveoli each minute, assuming the breathing rate is 10 breaths/min, the tidal volume is 800mL/breath, and the nonalveolar respiratory system volume (dead space) is 150mL? A. 5000mL B. 9500mL C. 6500mL D. 7850 mL
6500mL Of the 800 mL of air that enter the lungs in a single breath (tidal volume), only 650mL reach the alveoli per breath (800mL - 150mL). Therefore the net volume of air that reaches the alveoli each minut is equal to 650mL/breath multiplied by 10 breaths/min, or 6500mL.
Thermal expansion formula for change in length
= alpha * original length(m) * change in temp
Delta G with little circle =
= free energy of formation of products - free energy of formation of reactants
Uterus
A hollow muscular organ in the pelvic cavity of the female, in which the embryo is nourished and develops before birth
Organisms which can run metabolic pathways with or without the presence or absence of oxygen are called: A. Facultative anaerobes B. Obligate anaerobes C. Obligate aerobes D. Protoplasts
A. Obligate anaerobes cannot function in the presence of oxygen while obligate aerobes cannot function in the absence of oxygen. Protoplasts are bacteria (or other microorganisms) which have lost their cell walls; this says nothing about their metabolic pathways.
Which of the following areas, if interconnected, may lead to someone experiencing a type of synesthesia? A. Medial geniculate nucleus and lateral geniculate nucleus. B. Superior olivary nucleus and inferior colliculus. C. Auditory cortex and medial geniculate nucleus. D. Visual cortex and the thalamus.
A. The correct answer will connect a part of the visual pathway to a part of the auditory pathway. Choice A is therefore correct: it links the lateral (visual) geniculate nucleus to the medial (auditory). Both structures in choices B and C are a part of the auditory pathway, and both structures in choice D are a part of the visual pathway.
Hyperglycemia of allows some animals to undergo extreme cold conditions. Which of the following would support this hypothesis? A. suppression of insulin secretion during extreme cold B. suppression of glucagon secretion during extreme cold C. slowing of glycogen catabolism in the liver during extreme cold D. increased sensetivity of all pancreatic endocrine responses during extreme cold
A. suppression of insulin would allow hyperglycemic conditions to exist. suppression of glucagon would lower blood glucose levels.
When 2.0 mL of 0.1 M NaOH is added to 100 mL of a solution containing 0.1 M HCLO and 0.1 M NaClO what type of change in the pH of solution takes place? A. a slight (<0.1pH unit) increase B. a slight (<0.1 pH unit) decrease C. a significant (>0.1 pH unit) increase D. a significant (>0.1 pH unit) decrease
A. the pH will increase because a strong base is added. The increase will be small because the base is being added to a buffer solution. (same amount of A- and Ha)
Energy of activation
Activated complex - energy of products
Which of the following best describes agnosia? A) A mood disorder B) Loss of ability to recognize people or objects C) Inability to produce speech D) Inability to mirror an action
B) Loss of ability to recognize people or objects Agnosia best describes the loss of ability to recognize people or objects.
Protein X appears before protein Y in a biological pathway. Researchers discover that increases in protein Y levels decrease transcription of protein X. This is an example of: A) Positive feedback B) Negative feedback C) Translational control D) Protein degradation
B) Negative feedback Negative feedback occurs when a protein downstream in a signaling pathway decreases flux through the pathway by decreasing activity of an upstream protein. Here, protein Y decreases transcription of protein X and therefore decreases flux through the pathway (choice B is correct). Positive feedback increases flux through a pathway, so protein Y would increase the transcription of protein X (choice A is incorrect). Translational control involves proteins, which are not upregulated in this question stem (choices C and D are incorrect).
What is the primary function of the small intestine? A) Maintain salt homeostasis in the body B) Nutrient uptake and absorption of water C) Enzymatic digestion of food D) Absorption of vitamins and minerals
B) Nutrient uptake and absorption of water The primary function of the small intestine is to absorb carbohydrates, proteins, and water (choice B is correct). The large intestine primarily functions to absorb vitamins, minerals, and additional water (choice D is incorrect). While the small intestine plays a role in both salt homeostasis and enzymatic digestion, these are not primary functions of the small intestine (choices A and C are incorrect).
Zinc (Zn²⁺) deficiency can lead to poor would healing, pressure ulcer formation, and impaired immunity. This is believed to be at least partially due to inactivation of the enzyme carboxypeptidase. What other metal cofactor might be used in vivo to maintain partial activity? A. Mg²⁺ B. Ni²⁺ C. Mo D. Se
B. To answer this question, first try to summarize the question. What cofactor could substitute for Zn²⁺ as a cofactor for carboxypeptidase? Now decide where the necessary information is. Like reactivity, metal cofactor similarity depends on oxidation state and place in the periodic table. Thus, Ni²⁺ is the best answer since it is divalent as well as being a transition metal.
A researcher wants to insert a series of genes too large to be practically transferred by a plasmid. The researcher places them into a viral capsid and infects a bacterium with the virus. This method of gene transfer is known as: A. Transformation B. Transduction C. Conjugation D. Vertical gene transfer
B. Vertical gene transfer involves a parent-offspring relationship where one organism receives genes from another through some form of reproduction. Transformation involves the uptake of genetic information directly from the environment, and not through some cellular or viral intermediate. Conjugation involves the transfer of genes directly between two bacteria. (B) is the correct answer as transudction is the transfer of genes through a viral intermediate.
A person through a snowball horizontally at 25m/s from a height of 20m. How far does the snowball land? A. 40 m B. 50 m C. 45 m D. 100 m
B. X = 1/2at^2, (use g for a) ball in air for 2 s. multiply time by velocity
As a result of being a weaker base than ammonia, hydrazine (N2H4); A. has a smaller acidity constant (Ka) than does ammonia B. has a smaller basicity constant (Kb) than does ammonia C. can be protonated twice to form N2H^2+ D. forms hydrogen bonds in aqueous solution
B. basicity constant is a measure of the strength of a base. It is the equilibrium constant for the reaction of the base with water. The weaker the base, the lower the value of Kb
If oligonucleotides such as mRNA were not degraded rapidly by intracellular agents, which of the following processes would be most affected? A. the production of tRNA in the nucleus B. the coordination of cell differentiation during development C. the diffusion of respiratory gasses across the cell membrane D. the replication of DNA in the nucleus
B. the destruction of mRNA prevents continuous protein production, allowing the cell to change its protein expression over time. coordination of cell differentiation during development is extremely sensitive to the timing of mRNA turnover
Consider an organism that has three pairs of chromosomes, AsBbCc, in its diploid cells. How many genotypically different kinds of haploid cells can it produce? A. 4 B. 8 C. 16 D. 32
B. this can be calculated by using the formula 2^n. Where n is the haploid number of chromosomes, in this case, n=3. 2^3 = 8
Epidermis
Basale, Spinosum, Granulosum, Lucidum, Corneum
Which of the following neurotransmitters has an effect on mood most similar to that of endorphins? A. GABA B. Dopamine C. Serotonin D. Acetylcholine
C. Endorphins are mood enhancers. Of the answer choices, serotonin is the only one that has a similar effect on mood, which is why selective serotonin reuptake inhibitors (SSRIs) are prescribed as a treatment for depression.
What would be the expected pKa value for the amino group on the amino acid glycine? A. Between 0 and 2 B. Between 2 and 7 C. Between 7 and 10 D. Between 10 and 12
C. Most amino acids have pKa values that are 2-3 for their α-carboxylic acid group and between 9-10 for their α-amino group. A few amino acids have groups outside this range, but which amino acids and the exact values are beyond the scope of the exam; you should, however, know this general range.
Which is a feature of noble gases? A. They are polyatomic B. They are unstable C. They have a low boiling temperature D. Their outer shell of electrons is relatively empty
C. Noble gases are monatomic gases with low chemical reactivity. Their shell of valence of electrons is full, and therefore they are stable. They boil at low temperatures due to the presence of weak forces between the atoms, thus (C) is the correct answer.
Arginine has a pKa of 12.48. At which pH will >50% of the R-groups in a solution of arginine be positively charged? A. 13.58 B. 12.48 C. 11.09 D. Cannot be determined from the information given
C. When the pH = pKa, the half-equivalence point is reached, indicating that half of the substance is protonated and half is deprotonated. When we fall below the pH, more will be protonated than deprotonated. Because arginine is a basic molecule with nitrogen atoms in its functional group, they are positively charged when protonated. Hence the answer is (C) because most will be protonated and thus positively charged below the pKa.
When hexanoic acid reacts with ammonia: A. pentanamide is formed. B. hexanamide is formed. C. pentanamine is formed. D. hexanamine is formed.
Carboxylic acids can react with ammonia in a nucleophilic acyl substitution reaction to form amides. Since the carbon chain is not shortening, they should have the same root word for number of carbons. Therefore, when hexanoic acid reacts with ammonia, hexanamide will be formed.
what does cognitive dissonance mean?
Cognitive dissonance is the uncomfortable mental state that an individual experiences when she has a conflict between an attitude and a behavior
Which of the following blood types is the universal acceptor? A) O B) A C) B D) AB
D) AB Type AB blood is the universal acceptor because it can recognize all blood antigens (choice D is correct; choices A, B, and C are incorrect).
An alkene is brominated at two points, resulting in a final molar mass of 202. What is the molecular formula of the starting compound assuming the only functional group is an alkene? A. C₂H₆ B. C₂H₈ C. C₃H₈ D. C₃H₄
D. Knowing Br has a molar mass of 80 and two bromine atoms are incorporated into the alkene, a total of 160 amu are due to the added bromine. With the remaining 42 amu, we know there must be fewer than 4 carbons but more than 2. With 3 carbons, contributing 36 amu, and one double bond, the remainder must be due to hydrogens. Hence the empirical formula must be C3H4.
The choices below show the changes in bone density, calcitonin secretion, and PTH breakdown products in four patients. Which patient may have a tumor secreting PTHrP? A. BD: ↓, C: ↓, PTH BP: ↑ B. BD: ↓, C: ↑, PTH BP: ↑ C. BD: ↓, C: ↓, PTH BP: ↓ D. BD: ↓, C: ↑, PTH BP: ↓
D. PTH secretion is under the control of a negative feedback loop. If calcium levels go up due to the presence of a tumor secreting PTHrP, blood calcium concentration will begin to rise and PTH secretion (and its breakdown products) will go down. Calcitonin will be secreted in response to the increased blood calcium concentration, and bone density will go down because the PTHrP is stimulating breakdown of bone.
Which compound reacts with a base to form a salt and water? A. NaOH B. Na₂CO₃ C. NaCl D. CH₃COOH
D. The only acid that is listed is CH3COOH. Acids react wth bases to form salt and water.
Which of the following is equal to a change in momentum of an object? A. force B. acceleration C. velocity D. impulse
D. Impulse = ForceΔtime, impulse = Δmomentum
How is the speed of a sled and rider affected when they start at half the height of their original location? A. slower by a factor of 4 B. slower by a factor of 2(2)^1/2 C. slower by a factor of 2 D. slower by a factor of 2^1/2
D. V = (2gh)^1/2 at lower height v = (1/2V heigh)^1/2. V slower by 2^1/2
The intensity of a cell phone transmission received at the switching station is proportional to the power used by the phone and inversely proportional to the square of the distance between phone and station. Which combination of power and distance will provide the highest signal to be picked up by the switching station? A. 0.6 W, 2 miles B. 0.6 W, 3 miles C. 3 W, 5 miles D. 3 W, 4 miles
D. must calculate P/r^2 A. (0.6/4) W/mile^2 B. (0.6/9) W/mile^2 C. (3/25) W/mile^2 D. (3/16) W/mile^2, this is the biggest
equation linking standard cell potential and k (using ln)
E˚ = (0.0257V/n) * ln k -v is for volts not volume-
T or F? in DNA replication, DNA polymerase can only initiate DNA replication following the placement of a RNA primer by the enzyme DNA primase. explain.
False! the enzyme that makes RNA primer is RNA primase not!! DNA primase
T or F, explain: The electron transport chain produces NADH and ATP following oxidation of electron carriers.
False. ETC UTILIZES NADH to produce ATP, it doesn't CREATE NADH
How are nucleotides linked?
Linked by phospho bonds between sugar base (3' end) & phosphate group (5' end)
Hawk-Dove game (game theory)
Model behavior: struggle between 2 parties for shared food resource
Five Factor Model
OCEAN: openness, conscientiousness, extraversion, agreeableness, neuroticism
Changing what aspect of a mirror will change its focal length
Radius of curvature
Friction force of a block being pulled by a string on a flat surface moving at constant speed
Tcostheta where T is the tension in the spring, and theta is the angle between the spring and the block
Which characteristic distinguishes fungi as eukaryotes? A. They have cell walls B. They contain ribosomes C. They contain mitochondria D. They exhibit sexual reproduction
They contain mitochondria A characteristic that distinguishes eukaryotes from prokaryotes is that they contain membrane bound organelles
If you let bacterial cells form a colony in an experiment, what is the independent variable
Time at which the sample is collected (NOT NECESSARILY THE TIME THE BACTERIA ARE EXPOSED TO THE SAMPLE)
Bacterial Gene recombination
Transfer: Genes from surrounding --> Cell --> Genome Conj: genes transfer via bridge between bacterium Transduc: bacteria + viral progeny --> bacterium -NEW phenotype Transposon: genes in/out genome -NEW phenotype
Neural changes
Trophoblast (placenta), Inner cell mass (organism), Notochord (neural fold), neural crest (PNS)
What's Vmax? what's Km?
Vmax = the reaction rate when the enzyme is saturated Km = substrate concentration at which the reaction rate/velocity is half its max
is a peptide bond rigid?
YES! rigid and planar AKA it has no rotation
electron affinity
affinity to steal electrons in a ionic bond
what hormone conserves sodium and water at the expense of potassium in the distal convoluted tubule and collecting duct this increasing fluid reabsorption and increasing blood volume and pressure
aldosterone
which magnetic field is higher in energy, alpha or beta? why?
beta, bc it takes energy to go against the external magnetic field
ksp values are something to the -10 while kf values are way
bigger
peptide bond
carboxyl group of amino acid attacks the amino group of the other it has resonance and is planar molecular geometry partial double bond character
what is a fatty acid composed of?
carboxylic acid + hydrocarbon chain
just noticeable difference
change/original 105 diff than 100 so 5/100= 5% so 200lbs should be +/- 10 lbs
ectoderm gives rise to the
epidermis, lense of eye, inner ear, and the adrenal medulla and the nervous system NEERVOUS SYSTEM GEEZUZ
when solubilities of compounds are different what experimental approach is best way to separate reactants from products
extraction
the evolutionary phenomenon where certain areas of the world show a much higher frequency of particular alleles than other areas is known as the
founder effect
"gingiva" ???
gums
amphipathic
having both a hydrophilic region and a hydrophobic region
If someone loses their job and gets a similar amount of income through SSI, what type of mobility is this
horizontal
Thomas theorem
if people perceive something as real, it is real in consequence
What is the end of the small intestine called?
ileo-secal valve
ascending loop of henley is
impermeable to H2O
The Ka/K0 ratio is correlated with
increased substrate binding
how does epinephrine affect beta-oxidation?
increases it
as you move DOWN a reduction potential table, the strength of reducing agent increases or decreases?
increases!
as you go up the standard reduction table, the ability to get reduced increases AND the strength as an oxidizing agent increases/decreases?
increases! since the substance itself become more reducible
What happens when a battery, resistor, & capacitor are added in series?
initial voltage is 0 & as charge accumulates, voltage rises & curve is asymptotic
what do we mean when we refer to "inner leaflet" and "outer leaflet" ?
inner leaflet = the phospholipid layer of the phospholipid bilayer thats on the intracellular side outer leaflet = on the extracellular side
hormone secondary messenger, what hormones use them?
instead of the hormone binding to the receptor and directly causing the effect, it stimulates a cascade of events/secondary messengers inside the cell - used by protein hormones + catecholamine (aka adrenal medulla hormones)
parathyroid gland
its hormones + - the 4 patches on the thyroid gland; regulates blood calcium levels - hormone: PTH (parathyroid hormone)
4 structures of proteins
kind of bonds + 1. Primary; actual aa sequence (peptide bond) 2. Secondary; H-bond 3. Tertiary; bonds between distant AA within the SAME polypeptide (hydrophobic interactions, van Der Waals, h-bond, disulfide bridges) 4. Quaternary; same forces as tertiary but within DIFFERENT polypeptide chains
what is it called when a membrane protein exists in the middle of the 2 layers?
lipid-bound protein
What are terpenes?
made up of repeating units of isoprenes
albumin
major osmoregulatory protein of blood also plays a role in transporting fats
potential energy formula=
mgh
What gets reabsorbed in the DCT?
more ions and imp stuff
Cognitive neoassociation model
more likely to respond to others aggressively when we are feeling negative emotions
product of grignard reagent
new cc bonds
effect of glucagon
opposite of insulin; raises blood glucose levels
effective magnetic field =
original magnetic field - induced (electron) magnetic field
What part of the ETC has the highest attraction for electrons?
oxygen
NAD is composed of 2 nucleotides joined by their ____
phosphate groups
what is the main component of the cell membrane?
phospholipids
Functions of hair
physical protection, trap air to ↑ heat retention, provide a lever to ↑ sensation, trap sweat to cool body
Osmotic Pressure equation
pi = i MRT pi = osmotic pressure i = van't hoff factor M = molarity R = gas constant T = temperature
cochlea detects
pitch intensity of sounds
Buffering region (flat)
point where concentration of acid & base are equal
how to form disacharide (4 steps)
pronation of sugar nuc attack loss of h2o loss of proton
kinetochore forms at end of
prophase
Which of the following correctly depicts the Hardy-Weinberg equation? A) p
q = 2 B) p2 + 2pq + q2 = 1 C) 2p + q = 1 D) p3 = 1 + B) p2 + 2pq + q2 = 1 The Hardy-Weinberg equation predicts the frequency with which an allele occurs in a population and is correctly depicted by answer choice B, where p represents the frequency of the dominant allele while q represents the frequency of the recessive allele (choice B is correct; choices A, C, and D are incorrect).
reactants and product of esterification. how does it happen?
rxn where carboxylic acid becomes an ester - occurs by the carboxylic acid reacting with an alcohol in the presence of an acid
social stratification
system by which society ranks categories of people in a hierarchy
face validity
test APPEARS correct
Oogenesis
the production, growth, and maturation of an egg
Empiricism
view that knowledge originates in experience & science should rely on observation/experimentation
what is released in a peptide bond
water
3 types of islet cells
what they release + 1- alpha-islet cells: release glucagon ===> breaks down glycogen into glucose (makes glucose) 2- beta-islet cells: release insulin ===> opposite of glucagon (breaks down glucose) 3- delta-islet: release somatostatin ===> "stop" hormone which stops the effects of all other hormones
name the 4 mouth glands
what they release + 1- parotid gland 2- submandibular gland 3- sublingual *all 3 release a-amylase which breaks down carbs* 4- von ebners gland: releases enzyme called LINGUAL LIPASE which breaks down lipids
electronegativity:
A measure of the ability of an atom in a chemical compound to attract electrons
brainstem
primitive, eating, breathing
recombination frequency
prob of 2 alleles being crossed over in meiosis
Michealis-Menton plot
produces hyperbolic curve
Ka large shifts towards
products (stronger acid) pKa is lower (dissociates more
venturi effect (when a fluid flows through a constricted section of a pipe)
reduction in fluid pressure and increase in velocity of fluid
behaviorist perspective
related to external stimuli experienced
adiabatic on pressure vs volume graph
slopes down not straight line
Personality disorders are ego ______
syntonic (believe they are normal)
Phase change
temp is constant
during phase change temperature does what
temperature remains constant
instinctual drift
tendency for animal to drift back from learned response to innate response
out-group homogeneity
tendency to view all individuals outside our group as highly similar
Most viral proteins are produced directly by
translation of viral nucleic acids
Positive vs Negative punisher
Positive: adding a stimulus that decreases behavior Negative: removing a stimulus to decrease behavior
Attitude Components
cognitive (beliefs & ideas), affective (emotional experience), behavioral (responses/actions)
what recombinant process relies on F plasmid
conjugation
sensory receptors
electromagnetic radiation receptor ionic receptor norciceptor
Aufbau Principle
electron occupies lowest-energy orbital that can receive it
What cellular component facilitates membrane fusion
endosomes
What makes up the "portal triad"?
portal vein, hepatic artery, common hepatic duct
give pathway of hypothalamus hormones: GnRH, CRH, TRH, GHRH, PIF
-all ANTERIOR pituitary- 1) GnRH ====> FSH/LH ====> gonads 2) CRH ====> ACTH =====> adrenal glands 3) TRH ====> TSH ====> thyroid 4) GHRH =====> GH ====> directly stimulates growth 5) PIF =====> prolactin ===> directly stimulates milk production
Diffraction
-bending of a wave as it moves around an obstacle or passes through a narrow opening -reducing aperture --> ↓ resolution -occurs with ALL waves
RNA
-rNA: ribosome, protein synthesis -mRNA: DNA --> Ribosome (transcription) -tRNA: RNA --> Protein (translation) -hnRNA: synthesize DNA template (antisense) -RNA I: rRNA -RNA II: hnRNA & snRNA -RNA III: tRNA & 5s rRNA
Function of aluminum
-replace metal ions in enzyme cofactors & substrates (impacts protein function) -only dissolves in acidic soln
Stages of muscle contraction that require ATP binding &/or hydrolysis
1) Dissociation of myosin head from actin 2) Conformational changes that move myosin and actin relative to one another 3) Reuptake of calcium into sarcoplasm
amygdala
fear response
pyrimidines are: purines are: - which ones have the double rings?
pyrimidines: cytosine, uracil, thymine purines: guanine, adenosine - purines are double ringed
adaptive radiation
rapid emergence of multiple species from common ancestor
What property of the vocal cords is altered to allow speech production
tension
cofators are
things that help enzymes and are not other enzymes themselves if they are enzymes they're called coenzymes
what does a reaction of carboxylic acid
thiol produce? + thioester bond
If red litmus paper is dipped into Na2CO3 solution, it will
turn blue, because carbonate + water --> OH-
Where is proline likely to be found
turn in B-pleated sheet -it's very rigid and disrupts coils
cognitive dissonance
unpleasant tension resulting from two conflicting thoughts or beliefs -Change attitude to match behavior -Eat bad food --> Feel the need to exercise
Why is random assignment important?
used to eliminate confounding/extraneous variables all subjects have an equal chance of being assigned to any group or condition in the study
What set up will make a person with a severed corpus callosum say "ball" after a researcher asks "what do you see?"
"Ball" projected to RVF, "room" projected to LVF
dependency ratio
# of dependent people compared to # of productive people
standard cell potential
+1.1
internal validity vs external validity
- Internal Validity: The ability of your research design to test your hypothesis. Does it test what it's designed to? - External Validity: The degree to which a study's results can be extended beyond the limited research setting and sample (generalizability).
Neurotransmitters
-Acetylcholine: SNS (voluntary), PNS, CNS (alertness), attention -GABA: stabilizer (depressants ↑ it) -Dopamine: Smooth movement, posture stability
Electrolytic vs Galvanic cell
-Electrolytic: G (+), nonspont, EMF (-), K < 1. Charging. Anode: + Cathode: - -Galvanic: G (-), spont, EMF (+), K > 1. Discharging. Anode: - Cathode: +
Waves
-Electroneg: transverse wave -Longitudinal (sound): same direction -Transverse (light): perpindicular -Traveling: shifting point of max/min (propogation) -Standing: open/closed pipes, no propogation
Bones
-Flat: skull/ribs, red bone marrow, high blood -Long: Hands/feet/arms/legs, yellow bone marrow, low blood -Irregular: vertebrae
Lobes
-Frontal: Impulse, speech, motor (prefrontal, primary cortex, Broca's area) -Parietal: somatosensory cortex, spatial, orientation -Temporal: Sound, memory, emotion (auditory, wernicke's area, limbic system) -Occipital: visual
2 types of synthesis (BOTH result in racemic/inactive mix)
-Gabriel: form amino acid. Nuc (pthalamide). Electro (methyl carbon). LG (Br). 2 SN2, hydrolysis, decarbox -Strecker: form amino acid. Condensation, nuc addition, hydrolysis. Intermed (imine, amine, nitrile)
PPP
-HMP shunt, cytoplasm (no membrane bound) -Produces: NADPH / Sugar -Rate-limit: G,6-PD Activated by: NADP+ & Insulin Inhibited by: NADPH
Hexokinase vs Glucokinase (both trap glucose)
-Hexokinase: ↓ km, ↓ vmax, ↓ glucose, almost all tissues, Inhib: G6P -Glucokinase: ↑ km, ↑ vmax, ↑ glucose, liver & pancreatic β-cells, Inhib: Insulin
Ketolysis vs Ketogenesis
-Ketolysis: fasting, periph tissue, acetyl-coA, ↓ energy -Ketogenesis: fasting, liver, acetyl-coA
Aldosterone
-Water reabsorption in blood -Released: ↓ blood volume/pressure -Steroid hormone, produced by adrenal cortex -Absorbs more Na+, ↑ blood volume/pressure, -Concent of blood DOES NOT CHANGE
irreversible inhibition
-active site is made unavailable or enzyme is permanently altered -Requires strong bond (Covalent, disulfide bridge)
lamarak inheritance
"use disuse" inheritance biology can alter in individuals due to how you use it . proven wrong for biology can be compatible when discussing cultures
Ionic radius is determined by:
# of valence e- & e- shells
Volume entering alveoli per minute
(volume/breath - dead space)*breaths per minute
Scientists have developed a dye for galactose, which turns darker shades of blue as the concentration of this monosaccharide increases (dose dependent). In an experiment using bacteria that can metabolize both lactose and glucose, researchers set up test tubes as shown in Table 1. A plus sign indicates a sugar was added to the test tube, and a minus sign indicates the sugar is absent. Assuming bacterial concentrations stay constant, which test tube will show the strongest blue color? Tube Lactose Glucose A
+ B + - C - + D - - + The lac operon that controls lactose digestion in prokaryotes normally operates at a very low basal level, and is upregulated by the presence of its substrate. Lactose is a dimer of galactose and glucose. The absence of glucose leads to an increase in cAMP, because now the cell must rely much more heavily on the lac operon for energy. This sets off a cascade of events that upregulate the enzymes that cleaves lactose. The presence of lactose and absence of glucose will lead to the most galactose and thus will dye the most strongly blue (Answer B).
Estrogen
+ feedback (follic) & - feedback (luteal)
Diamagnetic materials Paramagnetic materials ferromagnetic materials
- repelled materials are repelled external B temporary effect - Paramagnetic materials are attracted external B temporary effect - ferromagnetic materials can be durably magnetized by external B
acidemia vs alkalemia
-Acidemia: blood pH is ↓ -Alkalemia: blood pH is ↑
Types of Reversible Inhibition
-Comp: binds to active site (Km ↑, Vmax same) -Noncomp: binds w/ equal affinity to enzyme & E-S complex (Km same, Vmax ↓). Lineweaver-Burke plot -Mixed: binds w/ unequal affinity to enzyme & E-S complex (Vmax ↓, Km dependent) -Uncomp: binds to E-S complex (Vmax ↓, Km ↓). DOES NOT alter slope of Lineweaver-burke plot
Equation
-Current: Q/Δt -Index of ref: n = c/v -Snell's Law = n1sinθ1 = n2sinθ2 n2>n1 light bends toward normal n1>n2 light bends away from normal -Frequency: f = v/ λ -Speed: c = f λ -Period: T = 1/f -Intensity: I = P/A -Heat of rxn: q = mcΔT -Work: W = Fd = PΔV = ΔE -Power: P = W/Δt -Density: ρ = m/v -Pressure: P = F/A -Weight/Buyoant : W = ρgV -Coulomb: F = kq1q2 / r^2 -Resistance: ρL/A -Power/resistance: P = IV = V^2/R = I^2/R -Mass defect: E = mc^2
Organs
-Duodenum: secrete lactase. Enteropeptidase (trysinogen --> cascade), Secretin (↓ motility), & cholecytokinin (bile release) -Pancreas: Secretes trypsin & carboxypeptidase. Amylase, peptidase, Lipase -Stomach: Mucous (protect, pH) ,chief (pepsinogen), parietal (HCL/intrinsic factor), G-cell (gastrin for motility) -Kidney: erythropoieten. Decrease O2 & produce RBC -Atria: ANP. excrete salt/H2O
HPG axis (Males)
-FSH --> spermatogenesis (sertoli cells) -LH --> testosterone (interstatial cells)
Reasoning fallacies
-Fund attribution error: assign reasons to behavior -Hindsight bias: seeing past events as more predictable than they actually were -Self-serving bias: personal success (internal) & failures (external) -Confirmation Bias: more influenced by info that confirmed beliefs
Types of Aphasia
-Global: Speech is absent -Broca's: can't speak -Wernicke's: can't understand speech -Conduction: can't repeat what they hear -Anomic: can't produce correct words
innate immune system
-Noncellular: Skin, lysozyme, gut, interferon (prevent viral rep), complement -Cellular: Macrophage (immune), Natural killer (infected/cancer), Granuloytes (neutro,baso,eusino)
Passive vs active exhalation
-Passive: diaphragm/lung relax, volume of chest cavity ↓, ↑ pressure in intrapleural space, air is pushed out -Active: internal intercostal muscles ↓ volume of thoracic cavity
Types of modifications
-Post-transcrip: 5' cap, 3-poly a tail, spliceosome, introns removed, exons joined, isoforms -Post-trans: chaperone folding, quaternary, protein cleavage, covalent addition
Types of errors
-Type I (alpha, false +): null incorrectly rejected -Type II (false -): fail to reject null
What does the body do when there is a loss in blood volume
-Water is reabsorbed from kidney -↓ urine & ↑ urine osmolarity
Order reactions
-Zero: constant, only affected by temp/catalyst. straight, -k slope -1st: non-constant, nonlinear, -k slope -2nd: non-constant, nonlinear, k slope -Broken: non-integer -Mixed: rate changes over time
Micelle
-absorb fat -Hydrophobic core & hydrophilic exterior
Descending of protons
-affected by magnetic field -J-value: measures degree of splitting & frequency
Gluconeogenesis
-cytoplasm, mito, liver, kidney -reverse of glycolysis -Pyruvate --> glucose -Rate limit: F1,6-BP Activated by: ATP (direct) & Glucagon (indirect) Inhibited by: AMP (direct) & insulin (indirect)
What is the benefit of conjugating proteins?
-direct delivery -> organelle/membrane -add cofactor
Photoelectric effect
-emission of e- from metal when light shines -photon strikes atom with ↓ work -KE DOES NOT depend on intensity
ETC
-inner mitochondria -uses free energy to pump protons from matrix --> intermembrane space - e- carriers: CYT-C, Ubiquinone, FADH2, NADH Halted by: buildup of H+ ions in inner membrane or ↓ ATP production
Citric acid/Krebs
-mitocondrial matrix, oxidative carbox -succinate --> fumurate (intermed) --> malate -Produces: 6 NADH, 2 FADH2, 2 GTP -Citrate synthase, Isocitrate, alpha-ketoglut Inhibited by: ATP, NADH
Enzymes
-stabilizes transition site (provides binding energy) to lower activation energy -Affect rate of rxn by: altering pH, co-localizing substrate, & altering substrate shape
Trends
-surface area ↑ = Current ↑ -↑ [ ] : ↓ transmittance & ↑ absorbance -P-value > 0.05 : Fail to reject null -P-value < 0.05 : Reject null -Mean > median : Skewed right -Mean < median : Skewed left -As displacement ↓ : Amp & volume ↑ -Refraction affects speed & wavelength -Power depends on: current & voltage -↑ distance : ↓ Efield -As angle ↑: Normal force & frictional force ↓ - + charge: ↑ --> ↓ - - charge: ↓ --> ↑
What is the role of myelin?
-surround axon & speed up action potential -insulates axon -alcohols are added as poor conductors
Reaction rate
-↑ [ ] reactant --> ↑ collisions -↑ temp --> ↑ KE -add catalyst --> ↓ Ea, ↑ stability, ↑ rate (total amount of product/time), NO affect on [ ] -change medium
Nucleophilicity
-↑: with ↑ electron density, ↑ electroneg, & ↓ hindrance -Protic solvents can inhibit this by protonating the molecule or via hydrogen bonding.
find mass of 300ml of water when density of water at 80degrees C is .975 g/ml
.957 * 300
What's the max number of calories provided by a molecule that is not digested
0 Cal
1 pascal
1 N/m^2
what things does the duodenum receive?
1- chyme from stomach 2- bile from the gallbladder 3- enzymes from pancreas
2 steps of semen transport
1- erection: blood vessels get dilated in penis 2- ejaculation: discharge of the semen from the penis
5 functions of testosterone
1- in development: makes the reproductive organs MALE 2- Stimulates spermatogenesis 3- responsible for secondary sex characteristics 4- increases sex drive and aggression 5- stimulates erythropoietin production
what are the 4 ways of regulating hormone concentrations?
1- liver removes them from bloodstream and turns them into bile 2- kidneys filter them out 3- we sweat them off 4- negative feedback loop (esp. for thyroid)
what are the 3 components of a phospholipid?
1- polar phosphate head 2- glycerol backbone 3- 2 non-polar fatty acid chains
what molecules can pass through the lipid membrane bilayer? what cannot?
1- small non-polar molecules (fast) - gases 2- small polar molecules (slow) - water, ethanol 3- large non-polar molecules (slow) can't: large polar molecules + charged molecules
what are the 3 factors that affect membrane fluidity?
1- temp: as temp decreases, so does the fluidity 2- cholesterol: acts as a buffer 3- unsaturated vs. saturated fatty acids: more unsaturated = more fluid
what are the 2 functions of the testes?
1- where spermogenisis (production of sperm) takes place 2- where testosterone is produced
^14C has how many neutrons and protons
8 neutrons and 6 protons
Which of the following neurotransmitters is the MOST involved in voluntary muscle movement? A) Acetylcholine B) Epinephrine C) Norepinephrine D) Serotonin
A) Acetylcholine Acetylcholine is involved in voluntary muscle movement (choice A is correct). Epinephrine is involved in the sympathetic nervous system response (choice B is incorrect). Norepinephrine is involved in attention and consciousness (choice C is incorrect). Serotonin is heavily involved in regulating emotional states and moods (choice D is incorrect).
Researchers decide to purify a protein using a Nickel column. They most likely prepare the protein with which of the following tags? A) C-terminal His6 tag B) N-terminal Ala6 tag C) C-terminal Glu8 tag D) N-terminal Val8 tag
A) C-terminal His6 tag His6 tags are added to proteins (at either the N- or C-terminus) to allow the tagged proteins to bind to columns (choice A is correct). The other tags are generally not used in experiments, and they would not be used for a nickel column as His-tags are standard (choices B, C, and D are incorrect).
Which of the following is NOT a commonly used intercellular junction? A) Closed junction B) Gap junction C) Tight junction D) Desmosome
A) Closed junction Closed junctions are not an intercellular junction (choice A is correct). Gap junctions, tight junctions, and desmosomes are commonly used intercellular junctions.
A researchers sets up a simple series circuit with a single resistor. Over time, the resistance of the resistor decreases. Which of the following best describes the effect of a decreasing resistance on current, given a constant voltage? A) Current increases B) Current decreases C) Current remains the same D) Current can no longer be calculated
A) Current increases Ohm's law is V=IR where V = voltage, I = current, and R = resistance. By rearranging the equation to I = V/R, we see that decreasing R while holding V constant leads to an increase in I (choice A is correct; choices B, C, and D are incorrect).
Which of the following is NOT one of the six universal emotions? A) Disappointment B) Fear C) Anger D) Sadness
A) Disappointment Disappointment is not one of the six universal emotions (choice A is correct). The six universal emotions are fear, anger, happiness, surprise, disgust, and sadness (choices B, C, and D are incorrect).
What stage of the cell cycle do most differentiated cells function in? A) G1 B) S C) G2 D) M
A) G1 Cells spend most of their time in G1, which also includes the subset G0. Differentiated cells that are performing their specific function spend most of their time in this phase. Only cells that are dividing or preparing to divide spend time in the other stages (choices B-D are incorrect).
A non-diabetic patient eats a large meal and several hours later has extremely high blood glucose levels. An inactivating mutation in which of the following enzymes might explain this observation? A) Hexokinase B) Aldolase C) Phosphoglyceromutase D) Enolase
A) Hexokinase Hexokinase is an irreversible enzyme responsible for phosphorylating glucose to trap it in the cell. If hexokinase is inactivated, glucose will not be trapped, which means it is less likely to be taken up into the cells and will remain in the blood. Choices B-D are not involved in glucose uptake and represent later steps in glycolysis.
Researchers observe a certain histone posttranslational modification in euchromatin. Which of the following do they most likely observe? A) Histone 4 lysine 27 acetylation B) Histone 4 lysine 27 deacetylation C) Histone 4 arginine 4 methylation D) Histone 4 arginine 8 methylation
A) Histone 4 lysine 27 acetylation Euchromatin is associated with increased transcription due to opening of the chromatin structure. Lysine acetylation can open chromatin structure through charge neutralization (choice A is correct; choice B is incorrect). Methylation generally closes chromatin structure, though the role of arginine methylation is not entirely characterized (choices C and D are incorrect).
Researchers observe a surge in a neuropeptide called α-MSH immediately after eating. What hormone is likely to also be upregulated after a meal? A) Insulin B) Glucagon C) Somatostatin D) Norepinephrine
A) Insulin α-MSH is anorexigenic, meaning it decreases appetite, often after eating a meal. Insulin is also released after eating a meal in order to promote the uptake of glucose from blood (choice A is correct). Glucagon is released during periods of starvation to promote release of glucose into the blood (choice B is incorrect). Somatostatin blocks both insulin and glucagon (choice C is incorrect). Norepinephrine is released during the flight or fight response during which digestion is halted (choice D is incorrect).
Researchers are interested in studying a new G-protein coupled receptor (GPCR) called GPCR84. Which of the following mutations may researchers introduce to the protein to decrease GPCR84 signaling? A) Mutate the alpha subunit of GPCR84 so that it is locked in a GDP-bound form. B) Mutate the alpha subunit of GPCR84 so that it is locked in a GTP-bound form. C) Add an agonist ligand that binds to GPCR84. D) Express GPCR84 on cellular surfaces that are spatially close to agonist ligands.
A) Mutate the alpha subunit of GPCR84 so that it is locked in a GDP-bound form.
Which of the following is a mechanism by which an antibody helps mediate an adaptive immune response? A) Neutralizes antigen B) Blocks complement C) Restricts T-cell localization D) Phagocytoses antigen
A) Neutralizes antigen Antibodies can neutralize antigens by binding to them and preventing them from properly functioning (choice A is correct). Antibodies are known to activate and help direct complement (choice B is incorrect). Restricting T-cell localization is not something that antibodies do, and it would prevent the adaptive immune response (choice C is incorrect). Antibodies are proteins, not cells, so they cannot phagocytose antigens (choice D is incorrect).
A point mutation in the DNA sequence for an important protein causes a valine to stop codon mutation at residue 86. This is an example of a: A) Nonsense mutation B) Frameshift mutation C) Active site mutation D) Missense mutation
A) Nonsense mutation A nonsense mutation occurs when a point mutation leads to a stop codon and premature termination of the protein product (choice A is correct). A frameshift mutation is due to an insertion or deletion of bases (choice B is incorrect). The mutation might be an active site mutation, but there is not enough information given by the question stem to determine that the mutation is definitely in the active site (choice C is incorrect). A missense mutation occurs when a point mutation causes a single amino acid substitution (choice D is incorrect).
Researchers are studying a potential novel oncoprotein implicated in gastric cancer. RT-qPCR results show an upregulation of the mRNA transcripts for the novel protein. Which of the following is a potential mechanism by which transcription of the protein is upregulated? A) Opening of chromatin structure B) Histone deacetylation C) Increased ribosome synthesis D) Increased amino acid availability
A) Opening of chromatin structure Opening of the chromatin structure allows transcription factors to more readily access the DNA, leading to an increase in transcription, which produces mRNA transcripts. Histone deacetylation leads to a closing of the chromatin structure (choice B is incorrect). Ribosome synthesis and amino acid availability might indicate increased protein translation, not transcription (choices C and D are incorrect).
Which of the following is the start point of a cardiac muscle contraction? A) Sinoatrial B) Atrioventricular C) Bundle of His D) Purkinje fibers
A) Sinoatrial The electrical activation pathway of a cardiac muscle contraction follows the following path: sinoatrial node to atrioventricular node to the bundle of His to the Purkinje fibers (choice A is correct; choices B, C, and D are incorrect).
A student expertly cuts a cake in front of many friends at a birthday much more efficiently than when she cut another cake by herself earlier in the week. This action is best described by: A) Social facilitation B) Social loafing C) Obedience D) Conformity
A) Social facilitation Social facilitation describes the tendency of an individual to perform a simple task better when other people are around (choice A is correct). Social loafing describes the tendency of individuals to not work as hard when they are in a group (choice B is incorrect). Obedience occurs when an individual changes his or her behavior in response to an authority figure with the power to enforce the request (choice C is incorrect). Conformity occurs when an individual acts like his or her peers in an attempt to fit in (choice D is incorrect).
Which of the following cells has the ability to differentiate into the greatest number of cell types? A) Totipotent cells B) Multipotent cells C) Pluripotent cells D) Embryonic stem cell
A) Totipotent cells Totipotent cells have the greatest ability to differentiate, meaning they are the least lineage committed. Multipotent cells are the most lineage committed (lowest ability to differentiate) of the cells in this question (choice B is incorrect). Pluripotent cells and embryonic stem cells are identical terms, and they are more lineage committed then totipotent cells, but they can still differentiate into many cell types (choices C and D are incorrect).
An individual is playing a challenging flute song in front of a large audience. He is extremely anxious, and he does not perform as well as he did during practice. Which of the following best describes this situation? A) Yerkes-Dodson law B) Drive reduction theory C) Instinct theory D) Extrinsic motivation
A) Yerkes-Dodson law The Yerkes-Dodson law describes a relationship between performance and arousal. There is an optimal level of arousal in order to achieve an optimal performance, and extreme anxiety may lead to a suboptimal performance (choice A is correct). Drive reduction theory is a theory of motivation that states individuals are motivated to behave in a way that reduces drives, or internal needs (choice B is incorrect). Instinct theory states that people are motivated based on instincts present in our DNA (choice C is incorrect). Extrinsic motivation describes a reward given for a certain behavior (choice D is incorrect).
Which of the following is NOT a common type of cellular RNA? A) slpRNA B) lncRNA C) snRNA D) tRNA
A) slpRNA slpRNA is not a commonly used type of cellular RNA (choice A is correct). lncRNA stands for long, non-coding RNA (choice B is incorrect). snRNA stands for small nuclear RNAs that are involved in splicing (choice C is incorrect). tRNA stands for transfer RNA (choice D is incorrect).
Which of the following would proceed according to first order kinetics assuming an elementary reaction? A. Linearized glucose becoming cyclized in solution. B. Glucose and fructose being converted to sucrose by sucrose synthase. C. The synthesis of glucose-6-phosphate from glucose and ATP. D. The conversion of glyceraldehyde-3-phosphate and dihydroxyacetone phosphate to fructose bisphosphate.
A. A first order reaction depends only on the concentration of a single reactant, and can be the result of an auto-reaction (e.g. decomposition of an unstable compound). Higher order reactions depend on the concentration of multiple reactants. Since we are assuming elementary reactions, we can assume the reaction proceeds as written (i.e. they are not net reactions which can hide the rate-limiting step which has a different reaction order). The only option listed that involves a molecule only interacting with itself is (A) since glucose cyclizing only involves it reacting with itself. All of the others involve at least two reactants, both of whose concentrations would have an impact on the rate of the reaction.
Tumors in the brain can sometimes lead to the unilateral destruction of an optic tract. If an individual had a tumor in the right optic tract, which of the following would they have seen? A. Only the right side of the image through both the left and the right eyes. B. Only the left side of the image through both the left and the right eyes. C. The left side of the image through the left eye, and the right side of the image through the right eye. D. The right side of the image through the left eye, and the left side of the image through the right eye.
A. A lesion in the right optic tract would cause left eye temporal field and right eye nasal field loss. Thus, the entire left side of the image would be lost in both eyes, only allowing them to see the right side of the image through both eyes. Choice A gives the most accurate description of this condition.
The amount of pain experienced by someone depends upon other circumstances such as focusing on something else or hormones. This concept is related to: A. The gate-control theory of pain B. Weber's Law C. Signal detection theory D. Bottom-up/Top-down processing
A. A stimulus that causes pain is not always equal to the amount of pain perceived. Ronald Melzac's gate-control theory of pain suggests that there are neural gateways through which pain passes. These gates can be blocked, thereby blocking the pain.
Which of the following holds true for urine of an individual with an abnormally high concentration of circulating ADH? A. Hypertonic urine (compared to a normal individual) B. Hypotonic urine (compared to a normal individual) C. Isotonic urine (compared to a normal individual), because ADH will not affect urine concentration D. Isotonic urine (compared to a normal individual), however the specific ionic composition of the urine will be different
A. ADH, also called vasopressin, is a hormone released by the posterior pituitary and results in water preservation. It results in increased water reabsorption in the collecting ducts of the kidney nephron. Thus, urine will be more concentrated in an individual with high ADH, therefore the urine will be hypertonic. Thus, (A) is the correct answer.
Which of the following statements is FALSE regarding primary and secondary amines? A. Primary amines are in general stronger bases than secondary amines. B. Primary amines are less sterically hindered than secondary amines. C. Primary and secondary amines both have a lone pair of electrons on the nitrogen atom. D. Primary and secondary amines can both be used in the production of an amide.
A. Alkyl groups in general electron-density donating and will stabilize a positive charge on nitrogen, making secondary amines stronger bases than primary amines, in general. This makes (A) false and therefore the correct answer. (B) is true because primary amines have only one alkyl group whereas secondary amines have two. (C) is true because only quaternary ammonium cations will not have a lone pair of electrons. (D) is true because amides can be produced from either type of amine when reacted with a carboxylic acid.
Which of the following types of radiation is most likely to collide with molecules in epithelial cells? A. Alpha B. Beta C. Gamma D. Positron
A. Alpha emissions are the largest of the four types of radiation; they are helium nuclei without electrons surrounding them. Due to their sheer size, they are most likely to interact with surface molecules, whereas smaller types of radiation (particularly gamma) are much more likely to pass through epithelia.
What beat frequency would be heard between two tones played simultaneously at 20 Hz and 25 Hz? A. 5 Hz B. 45 Hz C. 0.20 Hz D. 0.25 Hz
A. Beat frequencies are the result of alternating constructive and destructive interference between waves and are calculated as simply the difference between two frequencies. In this case, the difference would be 5 Hz.
A membrane permeable only to water is placed between solutions A and B. Solution A contains 3 mM glucose and solution B contains 3 mM NaCl. In which direction will the water flow? A. From A to B B. From B to A C. Neither; there are 3 mM of solute in both solutions. D. Neither; there is no force to drive the water in either direction.
A. Because NaCl dissociates in water, each component of its dissolution counts as another solute. Since 3mM of NaCl is in the solution, that means there are 3mM of Na and 3mM of Cl, for a total of 6mM. Since the solute concentration is higher in solution B than in solution A, water will travel from solution A to solution B.
Which of these residues could best accommodate a turn in a β-pleated sheet in PrP^Sc? A. Proline B. Histidine C. Phenylalanine D. Tyrosine
A. Because of the forced kink in the protein chain that proline must introduce in a polypeptide, proline is an excellent amino acid for β-turns.
Overall, the production of biogas results in: A. a net positive change in entropy. B. a net negative change in entropy. C. no net change in entropy. D. a variable change in entropy.
A. Biogas is produced from solid organic materials. Converting solids to gases represents an overall positive change in entropy.
Pure HCl and HBr can both be found in gaseous states. The two gasses are placed in identical molar amounts into chambers of equal volumes. Assuming the two molecules are only equal in size, what is the relationship between the pressures of the different compounds? A. HCl has a lower pressure because it is more polar than HBr and its attractive forces cause less pressure against the chamber walls. B. HCl has a higher pressure because it is more polar than HBr and its attractive forces cause more pressure against the chamber walls. C. HBr has a lower pressure because it is more polar than HCl and its attractive forces cause less pressure against the chamber walls. D. HBr has a higher pressure because it is more polar than HCl and its attractive forces cause more pressure against the chamber walls.
A. Cl is more electronegative than Br (given by its position on the periodic table). Therefore HCl will have a stronger dipole and the molecules will have stronger attractive forces. These attractive forces cause less motion of the molecules since they sit tighter together, meaning the pressure of HCl should be lower than that of HBr. Of course, if we were working within the constraints of the ideal gas law, we would be able to ignore such effects and would conclude that the two pressures would be equal.
Which of the following methods would yield the most rapid calibration of a new thermometer? A. Placing two thermometers in a convection oven B. Placing two thermometers under an infrared heat lamp C. Placing two thermometers on a piece of heated metal D. All of the above are equally rapid
A. Convection ovens heat via both convection and radiation, and so choice A is correct. Choice B only involves radiation, and choice C only involves conduction.
Patients with high cortisol levels often suffer from obesity. Which of the following is a likely explanation for this observation? A. Cortisol increases insulin levels, resulting in increased deposition of fat. B. Cortisol increases levels of glucagon, resulting in an increase in appetite. C. Cortisol decreases secretion of TSH, resulting in decreased metabolic rate. D. Cortisol increases secretion of growth hormone, resulting in increased muscle mass.
A. Cortisol is a hormone secreted in response to stress. Cortisol increases levels of circulating blood glucose, which leads to increased insulin levels. This helps to prepare the body for fight-or-flight. However, in some diseases, cortisol is secreted inappropriately.
A human embryo is found to have malformation of the alar plate. If the embryo is viable, which of the following symptoms is the newborn likely to exhibit? A. Insensitivity to pain B. Quadraplegia C. Spina bifida D. Anencephaly
A. During neurulation, the alar plate differentiates into the afferent, or sensory, neurons. The most likely condition that would arise as a result of alar plate disorder, therefore, is a lack of sensation.
Electromagnetic radiation is a A. transverse wave only. B. longitudinal wave only. C. longitudinal and transverse wave. D. longitudinal or transverse wave.
A. Electromagnetic radiation is emitted as photons which travel as transverse waves. Longitudinal waves include sound waves which travel as pulses; their amplitude is in the direction of the wave. Transverse waves travel with their amplitude perpendicular to the direction of the wave.
Which of the following expressions describes the work done by air resistance on a falling object between the time when it reaches its terminal velocity and the time when it impacts the ground? A. mgh B. m(gh - ½v_terminal²) C. √2gh D. ½v_terminal²
A. For this object that has reached its terminal velocity (no acceleration), we know that the force of gravity is equal to the force of air resistance (Fg = Fterminal). Since Fg = mg, we know Fterminal = mg. We also know W = Fd, so therefore W = mgd where d is the height fallen, also known as h. The work done on the object is equal to the gravitational potential energy of that object from the height at which it falls because air resistance counteracts all the force that is acting on the object due to gravity. None of the other expressions properly sets up this relationship.
What is the byproduct of free radical chlorination of an alkane? A. HCl B. Cl₂ C. Cl⁻ D. H₂
A. Free radical chlorintion (or halogenation in general) splits the diatomic bond between the halogen atoms Cl-Cl to form 2 Cl•. One radical removes a hydrogen atom to form HCl and an alkyl radical. The alkyl radical then reacts with Cl-Cl to become halogenated and form another Cl• radical during propagation.
The pitch of a sound wave depends on: A. Frequency B. Wavelength C. Amplitude D. Speed
A. Frequency is what determines the pitch of a sound wave. A high pitch sound corresponds to a high frequency sound wave; moreover, a low pitch sound corresponds to a low frequency sound wave. This is because human ears detect fluctuations in air pressure, which are due to the period of a sound wave. With more time in between pressure points (large period), the frequency is low, and with less time in between pressure points (small period), the frequency is high.
A primary advantage of ganglia in vertebrates is their ability to A. process stimuli and responses faster than if the signal were to travel through the central nervous system. B. act as a backup to the central nervous system in cases where there is significant cerebral damage. C. detect stimuli that are finer than stimuli that are processed by the central nervous system. D. illicit a more complex response than the central nervous system.
A. Ganglia are collections of nerve cell bodies outside of the central nervous system. One major advantage to having ganglia in vertebrates (which have a central nervous system) is their ability to receive and process stimuli very quickly; the stimulus does not need to be sent to the central nervous system, processed, and sent back. Because ganglia are far less complex than the central nervous system, they cannot act as a backup, especially for cerebral function which is highly complex. This makes (B) incorrect. (C) is incorrect because stimuli are all still detected via neurons and there is no good reason for why ganglia are able to process finer stimuli than the central nervous system. (D) is incorrect because again, the ganglia are simpler than the central nervous system hence they cannot process more complex responses.
Stimulation of photoreceptor cells in the retina by light causes a hyperpolarization of the cell. This should have which of the following effects? A. Decrease in action potential frequency. B. Increase in action potential frequency. C. Decrease in length of the action potential. D. Increase in length of the action potential.
A. Hyperpolarization of a photoreceptor cell (a neuron) would cause the resting potential to decrease. This in turn could be expected to decrease the number of action potentials since an action potential is a result of a stimulus resulting in a cell potential increase. The hyperpolarization would therefore make the action potential more difficult and decrease its frequency. In fact, this is what happens in the retina during light stimulus; photoreceptor cells spontaneously depolarize until light strikes them, at which point they cease to depolarize.
Two bodies, one charged and one uncharged, come into contact. Which of the following options is (are) true regarding this event? I. If either of the bodies are poor conductors, they will both retain their charge. II. If both bodies are good conductors, they will both retain their charge. III. If both bodies are good conductors, protons will move from the charged body to the uncharged body. A. I only B. II only C. I and III only D. II and III only
A. II is incorrect since good conductors will tend to release or gain charges easily. III is incorrect since static charges are governed by the movement of electrons, not protons.
Air resistance is usually neglected for objects in motion, however it can be formalized to the equation F=-cv², where c is the air constant and v is the velocity. Which of the following correctly states the relationship of the graphs of velocity over time for a free-falling object with and without air resistance? A. Without air resistance, the graph is linear. With air resistance, the graph is non-linear. B. Without air resistance, the graph is non-linear. With air resistance, the graph is linear. C. Both graphs will appear linear. D. Both graphs will appear non-linear.
A. In studying the velocity vs time graphs, we can first look at the graph without air resistance. We know that acceleration is constant, thus velocity increases in a linear fashion (i.e., the object gains 9.8 m/s each second of motion). Thus this graph is linear. With respect to the graph with air resistance, we know that the velocity will not increase in a linear fashion, because the force on the object is nonconstant, rather is dependent on the velocity of the object. Thus (A) is the correct answer.
Which of the following genes would be expected to be found across the widest array of different organisms? A. Glucose membrane transporter B. Sodium-potassium pump C. Dopamine receptor D. Keratin
A. Keratin is an important protein in many animals but is not used by many other organisms. The same is true for dopamine and the sodium-potassium pump. However, since nearly all life uses glucose, the glucose transporter is found across all phyla and would be expected to be the most widely distributed gene.
The primary function of lysosomes is to A. digest macromolecules, organelles, and microorganisms. B. be released and used as extracellular defense mechanisms. C. produce ATP for the cell. D. transport macromolecules to and from the nucleus.
A. Lysosomes are a common organelle used for digestive purposes. They contain powerful digestive enzymes and low pH to digest and recycle various cellular components. They are not released to the extracellular environment, are not used for energy production, and are not used as transport vesicles for the nucleus.
The majority of mitochondrial proteins are synthesized on free ribosomes in the cytosol. The remainder of mitochondrial proteins are synthesized in the A. mitochondrial matrix. B. endoplasmic reticulum. C. nucleus. D. extracellular matrix.
A. Mitochondria possess their own ribosomes resembling prokaryotic ribosomes. These are used to synthesize unique mitochondrial proteins inside the matrix of the mitochondria since the matrix also contains the mitochondrial DNA. The endoplasmic reticulum is used primarily for translation of extracellular and membrane proteins; proteins are not translated inside the nucleus; and protein translation does not occur outside the cell, making (B)-(D) incorrect.
A chemotherapeutic that functions by inhibiting rapid cell division is applied to a body. Which of the following tissues would be most greatly affected? A. The epithelium of the digestive tract B. The muscle cells of the heart C. Neurons in the brain D. Osteoblasts in the bone
A. Of those listed, the only tissue that is undergoing rapid and persistent cell division is the epithelium of the digestive tract. Epithelia are constantly dividing and replacing their layers as a mechanism to protect the body. Therefore they are most greatly affected during treatment with chemotherapeutic drugs. Cells of the heart, neurons of the brain, and osteoblasts are not actively dividing and would thus be unaffected.
When treated with a strong oxidizing agent like CrO₃, benzaldehyde will most likely produce which of the following products? A. Benzoic acid B. Phenylmethanol C. Phenol D. Benzene and carbon dioxide
A. Oxidation of an aldehyde can lead to production of a carboxylic acid. Conversion to an alcohol would constitute a reduction reaction, making (B) and (C) incorrect. There would not likely be a decarboxylation reaction as this occurs with specialized reactions including decarboxylation of β-keto acids. We are told this is a reaction with a strong oxidizing agent and therefore we need to find the reaction that reflects that.
Which of the following conditions would be present in an oxygen-starved cell of an aerobic organism? A. An excess of NADH B. An excess of NAD+ C. An excess of ATP D. An excess of oxidative radicals
A. Oxidative radicals should be at their highest in a high-oxygen environment, making (D) incorrect. Because the aerobic organism uses oxygen to produce ATP, the ATP should not be in abundance making (C) incorrect. During glycolysis, NAD+, is converted to NADH as an essential component of the process. Later, the NADH will be consumed during the ETC. However, without the ETC (an aerobic process), the NADH builds up in the system. In the absence of ETC, this NADH is typically recycled to NAD+ by fermentation but there should be a buildup of NADH nonetheless.
Which of the following ions is the smallest? A. Ca²⁺ B. Cl⁻ C. I⁻ D. K⁺
A. Scanning the elemental forms of the ions, we can quickly eliminate choice (C) since iodine appears lower on the periodic table and thus has a larger atomic mass. This leaves us to compare Ca²⁺, K⁺ and Cl⁻. Each of these has the same number of valence electrons, essentially an argon core. Since anions gain electrons, they have greater electron repulsion and thus are larger in size. This eliminates Cl⁻, choice (B). Finally, atomic radius decreases from left to right on the periodic table due to increasing effective nuclear charge. Since calcium is right of potassium, Ca²⁺ would be smallest, making (A) the right answer.
The Ka for acetic acid is 1.8 x 10-5. In a solution of 35% acetic acid, which of the following species would be most abundant? A. HAc B. Ac⁻ C. H⁺ D. The answer cannot be determined with the given information
A. Since we are given the Ka of the acetic acid, we know it is a weak acid and therefore its dissociation equilibrium is shifted heavily to the left (towards the reactants). This means that in solution, the majority of the acid will be protonated making (A) the correct answer.
The T-cell receptor and B-cell receptor molecules (TCR and BCR) involved in immunological response are analogous to which of the following structures A. Immunoglobulins B. Phospholipids C. Lipopolysaccharide D. Tyrosine kinase receptors
A. TCR and BCR molecules are identical to immunoglobulins except for their constant regions which, instead of having an A, E, G, M, or D classification based on differing properties, have transmembrane regions which allow for specific interactions directly within the T and B cell once they encounter an antigen.
Which of these interactions found in collagen contributes the LEAST to its tertiary structure? A. The hydrogen bond between the carbonyl oxygen of glycine-126 and the carbonyl carbon of proline-180 B. A disulfide bond between cysteine-140 and cysteine-160 C. Ionic interactions between lysine-150 and aspartate-89 D. Lysine-hydroxylysine covalent cross-linking within α-chain 1 of tropocollagen
A. Tertiary structure is the three-dimensional shape of a protein that results from interactions between the side chains of amino acids. Those interactions, however, do not involve the protein's backbone. Choice A involves the backbone, and therefore is correct. Disulfide bonds (choice B) are classic components of tertiary structure. Ionic interactions between side chains (choice C) contribute to tertiary structure. Choice D discusses cross-linking within a chain; had this said cross-linking between different chain, this could be an example of quaternary structure rather than tertiary structure.
Which of the following adrenal cortical hormones is likely deficient in all patients with congenital adrenal hyperplasia? A. Cortisol B. Aldosterone C. Adrenal androgens D. Epinephrine
A. The adrenal cortex produces cordisol (glucocorticoids), aldosterone (mineralocorticoids), and adrenal androgens. Congenital adrenal hyperplasia causes derangements in the concentrations of these hormones. Mineralocorticoids and adrenal androgens are not uniformly low in all of these conditions. Thus, choice B and C may be eliminated. Epinephrine is synthesized by the adrenal medulla, eliminating choice D.
Patients with kidney failure often suffer from hypocalcemia in the setting of hyperparathyroidism. Which of the following processes occurs in the kidneys and accounts for this? A. Activation of vitamin D B. Calcium mobilization C. PTH secretion D. Calcium mineralization
A. The conversion of vitamin D from its inactive form to its active form requires hydroxylation in the kidney. This step activates vitamin D, allowing for increased absorption of calcium from the intestines. In kidney disease, phosphate is not excreted appropriately, resulting in complexing of calcium and phosphate, causing reduction of available calcium. Choices B and D occur in bones, not in kidneys. Choice C occurs in the parathyroid glands.
The semi-permeable membrane of the dialysis machine functions in a manner most analogous to which part of the kidney? A. Glomerulus B. Ureter C. Descending loop of Henle D. Vasa recta
A. The glomerulus functions like a sieve, allowing the filtration (movement from the circulation into the nephron tubule) of small molecules while blocking the filtration of the plasma proteins. The semi-permeable membrane serves an analogous function in the dialysis machine.
The voltage of a neuron decreases from a resting potential of -70 mV to -75 mV. Which of the following would be expected for this neuron? A. Decreased firing B. Increased depolarization from stimuli C. Sodium channels which decrease the rate of sodium influx D. All of the above
A. The neuron will not fire as frequently because it is in a hyperpolarized state. This implies that it will take a much higher stimulus in order to trigger an action potential. Thus, we know that option (A) holds true. Option (B) is false, because we do not know whether there will be increased depolarization from stimuli. Stimuli will likely provide the same magnitude of depolarization, however it may not be sufficient for an action potential (due to the reduced resting potential). Lastly, option (C) is false because we have no knowledge about how the sodium channels act. If (C) were true, that would imply that the cell would have a more difficult time becoming depolarized - we simply are not given this information in the problem. Therefore, (A) is the correct answer.
Overactive parathyroid glands can result in: A. the increased breakdown of bone. B. hypocalcemia. C. decreased kidney clearance of calcium. D. decreased calcium absorption in the intestine.
A. The parathyroid glands have important functions relating to the body's calcium and phosphate levels. By secreting parathyroid hormone (PTH), these glands can control the levels of these ions in the body. With an excess of parathyroid hormone in the blood, hypercalcemia is expected, as is increased calcium clearance by the kidneys. An increase in the amount of calcium in the blood can be due to the increased breakdown of the bone. This breakdown releases minerals and increases the flow of calcium from the bone to the blood. An increase in the calcium absorption in the intestine can also contribute to elevated calcium levels.
In an experiment, participants were played identical notes 5-15 times with random amounts of time between each note, between 5 and 15 seconds. Participants were asked to count the number of times the note was played. This experiment measures which type of attention? A. Focused attention B. Divided attention C. Selective attention D. Alternating attention
A. The participants are focused on a single task that is unchanging and presents no distractions: counting the same tone after it is played several times. Divided attention would involve responding to multiple different stimuli simultaneously; selective attention would involve maintaining attention despite outside stimuli; alternating attention would involve shifting focus from one task to another. This makes (A) the correct answer.
Motor vehicle accidents can frequently result in splenic rupture which requires that the spleen be surgically removed. In an individual who undergoes such a removal, which of the following effects would not be expected? A. Decreased red blood cell production B. Decreased filtration of red blood cells C. Decreased ability of the body to store red blood cells D. Decreased ability to fight certain infections
A. The spleen has a variety of functions in the human body. It serves to store red blood cells (RBCs) as well as filter RBCs. It contains a significant amount of immune cells which are significant in getting rid of certain bacterial infections. Option (A) is not a function of the spleen, rather a function of bone marrow. Production would not be affected. Thus (A) is the answer.
Which of the following conditions is LEAST likely to be comorbid with Parkinson's disease? A. Schizophrenia B. Depression C. Pain in the extremities D. Dementia
A. The symptoms of Parkinson's are a result of decreased dopamine production in the brain. Of the choices, schizophrenia is least likely to be comorbid with Parkinson's, as it is commonly thought to result from increased dopamine activity.
Which of the following best describes the response of the skeletal system to increased levels of PTH? A. Osteoclast activity increases because bone breakdown will raise blood calcium levels. B. Osteoclast activity decreases because high levels of blood calcium trigger bone formation. C. Osteoblast activity increases because bone remodeling will raise blood calcium levels. D. Osteoblast activity decreases because high levels of blood calcium trigger bone breakdown.
A. The systems that respond to PTH do so with the goal of raising blood calcium. Recall that osteoclasts are cells that break down bones, and osteoblasts are cells that lay down bone. Choice A is therefore correct because stimulation of osteoclasts breaks down bone, releasing calcium from bone into blood.
A carbocation is surrounded by two hydrogen atoms and a third group. Which of the following third groups bound to the carbocation would render the carbocation most stable? A. Methyl group B. Nitro group C. Fluoride group D. Carboxyl group
A. We are looking for a group which can supply electron density to the cation through an inductive effect. A methyl group will do this most effectively since alkyl groups are electron-donating while nitro, halide, and carboxyl groups are electron-withdrawing.
Wich graph best illustrates the relationship between speed of the transmitter away from the receiver and the increase in wavelength of the received signal? A. increases linearly B. speed in independent of wavelength C. decreases exponentially D. decreases linearly
A. increases linearly due to linear relation between relative speed (v) and change in detected wavelength in doppler equation for wavelength is delta wavelength/wavelength = v/c further more, graph A only one with increasing wavelength
When the number of photons incident on the cathode with energies above the value of the work function increases, which of the following quantities also increases? A. number o electrons ejected B. potential energy of each ejected electron C. magnitude of the electric field between the electrodes D. speed of electrons at the anode
A. number of electrons ejected. The number of photons only affects the number of electron ejected
which of the following properties is associated with the existence of glycine as a dipolar ion in aqueous solution? A. hight dipole moment B. high molecular weight C. low dielectric constant D. low solubility in water
A. problem states that glycine exists "as a dipolar ion in aqueous solution". High dipolar moments are associated with zwitterions
It was hypothesized that the decrease in blood flow to skin resulted from a change in the activity of the sympathetic nerves to the skin. Which of the following observations would support this? A. a change in the norepinephrine content of blood draining from the skin B. in vitro of contraction of the smooth muscle in skin blood vessels in response to acetylcholine C. a lack of epinephrine receptors in skin blood vessels D. in vivo dilation of the skin blood vessels
A. sympathetic nervous system uses norepinephrine
Sound of a known frequency, wavelength, intensity, and speed travels through air and bounces off an imperfect reflector wich is moving toward the source. Which of the following properties of the sound remains the same before and after reflection? A. speed B. Intensity c. frequency D. wavelength
A. within still air, the speed of sound remains constant. Apparent frequency increases because the reflector is moving toward the source of light
The peptide bond can best be characterized as which of the following functional groups? A) Carboxylic acid B) Amide C) Amine D) Ester
B) Amide A peptide bond is an amide, which contains a nitrogen attached to the carbon of a carbonyl group (choice B is correct; choices A, C, and D are incorrect).
Which of the following DNA regions is a highly transcribed protein most likely to be found? A) Heterochromatin B) Euchromatin C) Centromere D) Telomere
B) Euchromatin Euchromatin represents a more open chromatin structure, which corresponds to an increase in transcription. Heterochromatin represents a closed chromatin structure where transcription is lower (choice A is incorrect). Centromeres are structural DNA elements where microtubules attach during mitosis (choice C is incorrect). Telomeres are located at the end of the chromosome and are used to prevent chromosomal degradation (choice D is incorrect).
Which of the following is the equation given by Newton's second law? A) PE = mgh B) F = ma C) PV = nRT D) V = IR
B) F = ma Newton's second law states that force is equal to mass multiple by acceleration (choice B is correct). PE = mgh is the equation for gravitational potential energy (choice A is incorrect). PV = nRT is the ideal gas law (choice C is incorrect). V = IR is Ohm's Law for circuits (choice D is incorrect).
Which of the following best represents why a researcher uses more G's and C's than A's or T's while developing a PCR primer? A) G and C are larger and therefore more stable B) G and C form three hydrogen bonds, making them more stable C) A and T are larger and therefore less stable D) G can form non-canonical base pairs
B) G and C form three hydrogen bonds, making them more stable G's and C's are often used in primers because they form three hydrogen bonds, which makes them more stable than A's and T's (choice B is correct). A and G are purines (two rings) which are larger than C and T (one ring) (choices A and C are incorrect). All of the base pairs can engage in non-canonical base pairing (choice D is incorrect).
Which of the following is NOT true of biological catalysts? A) Speeds up the rate of a reaction B) Increases the equilibrium level of products C) Regenerates itself during the reaction D) It can be either a protein or a nucleic acid
B) Increases the equilibrium level of products Biological catalysts and catalysts in general do not affect equilibrium within a reaction. Catalysts affect kinetics (choice A is incorrect), but not the equilibrium amount of reactants and products. For example, if 5 reactants convert to 3 products in 1 hour, a catalyst might cause 5 reactants to covert to 3 products in 30 minutes. A catalyst would not, however, cause 5 reactants to covert to 5 products. A catalyst regenerates itself during a reaction so that it can undergo multiple cycles (choice C is incorrect), and both proteins and nucleic acids (i.e. ribozymes) can serve catalytic functions (choice D is incorrect).
Following a viral infection, a patient is not showing any respiratory symptoms or fever. What cycle is the virus most likely in? A) Lytic B) Lysogenic C) Invasion D) Protein production
B) Lysogenic The lysogenic cycle is where the virus integrates its own genome into the host genome, but it does not lyse the cell or produce lots of progeny yet. As a result, it may be undetected by the immune system. The lytic cycle occurs when the virus begins producing progeny and lysing host cells (choice A is incorrect). Invasion and protein production describe processes that the virus may use, but they are not actual cycles (choices C and D are incorrect).
Antigen-presenting cells use which of the following protein classes to present antigenic particles to immune cells? A) HMD B) MHC C) Antigen transferase D) PRMT
B) MHC Antigen-presenting cells present antigenic particles on MHC complexes.
Which of the following explains why X-linked diseases occur more frequently in males? A) Males lack the hormones needed to properly mask the disease-causing genes B) Males, unlike females, have only one X chromosome and therefore may not have a healthy copy of an allele present on the other X-chromosome C) Females are more likely to have no genotypic abnormalities D) Females are more likely to produce transcription factors that mask the disease-causing allele
B) Males, unlike females, have only one X chromosome and therefore may not have a healthy copy of an allele present on the other X-chromosome X-linked diseases occur more commonly in males because there is no healthy allele to compensate for the disease-causing allele (choice B is correct). Hormones or transcription factors do not generally mask the disease-causing allele (choices A and D are incorrect). Females are equally as likely to have genotypic abnormalities, but they are less likely to have phenotypic abnormalities (choice C is incorrect).
Which of the following cells has the lowest ability to differentiate into a large number of different cell types? A) Totipotent cells B) Multipotent cells C) Pluripotent cells D) Embryonic stem cell
B) Multipotent cells Totipotent cells have the greatest ability to differentiate, meaning they are the least lineage committed (choice A is incorrect). Multipotent cells are the most lineage committed (lowest ability to differentiate) of the cells in this question (choice B is correct). Pluripotent cells and embryonic stem cells are identical terms, and they are more lineage committed then totipotent cells, but they can still differentiate into many cell types (choices C and D are incorrect).
Which of the following amino acids is most likely to form pi-stacking interactions with a nucleotide? A) Serine B) Phenylalanine C) Alanine D) Methionine
B) Phenylalanine Pi-stacking interactions are formed between two or more conjugated rings stacked on top of one another. Phenylalanine is a conjugated ring that can form pi-stacking interactions with a nitrogenous-base in a nucleotide (choice B is correct). Serine, alanine, and methionine are not conjugated rings and therefore cannot form pi-stacking interactions.
A researcher is attempting to understand a temporal trend observed in p-STAT5 or p-ERK1/2 phosphorylation in which phosphorylation levels decrease over time. RT-qPCR might show upregulation of which type of enzyme? A) Transferase B) Phosphatase C) Oxidoreductase D) Ligase
B) Phosphatase The question stem states that there is decrease in phosphorylation. This might occur due to the removal of the phosphate group by a phosphatase, and RT-qPCR provides information about upregulated mRNA, which would be mRNA that encodes phosphatases in this case (choice B is correct). Transferases add molecules to other molecules (choice A is incorrect). Oxidoreductases engage in oxidation-reduction reactions (choice C is incorrect). Ligases join two molecules to form a chemical bond (choice D is incorrect).
A non-diabetic individual eats a large, carbohydrate-rich meal. Which of the following glycolysis enzymes is insulin most likely to upregulate? A) Phosphoglucose isomerase B) Phosphofructokinase-1 C) Phosphoglyceromutase D) Enolase
B) Phosphofructokinase-1 Phosphofructokinase-1 (PFK-1) is an irreversible enzyme, which means it is an important point for regulating flux, or flow, through glycolysis. After eating a large meal, insulin can upregulate PFK-1 activity through a series of steps, allowing glycolysis to proceed more quickly. Answer choices A, C, and D are reversible enzymes, so they are not good points for regulation and are not used as control points for flux through a pathway.
A researcher is studying a molecule with three chiral centers. The researcher obtains a racemic mixture after several steps of purification. Which of the following stereochemical designations could the researcher have obtained? A) S,S,S and R,S,R B) R,S,S and S,R,R C) R,S,R and S,R,R D) S,S,R and S,S,S
B) R,S,S and S,R,R A racemic mixture occurs when an enantiomer pair is present in equal amounts. Enantiomers have opposite stereochemistry at every chiral center (choice B is correct; choices A, C, and D are incorrect).
A mutation in the viral coding sequence for which enzyme would MOST likely inhibit HIV invasion and survival in a host cell? A) Actin B) Reverse transcriptase C) Protein arginine methyltransferase 5 D) Polymerase alpha
B) Reverse transcriptase HIV encodes a very small number of proteins in order to have a compact genome. One of these proteins is reverse transcriptase, which is needed to convert the ssRNA genome into DNA, so that it can be integrated into the host genome. Answer choices A, C, and D describe normal proteins present in humans but not necessary for a virus to have in its genome.
Which of the following best characterizes cocci bacteria? A) Rod-shaped B) Sphere-shaped C) Spiral-shaped D) Cone-shaped
B) Sphere-shaped Bacilli are rod-shaped bacteria (choice A is incorrect). Sphere-shaped bacteria are cocci (choice B is correct). Spiral-shaped bacteria are spirilli (choice C is incorrect). Cone-shaped bacteria are not commonly found (choice D is incorrect).
During which stage of the demographic transition model does the death rate fall while the birth rate remains constant? A) Stage 1 B) Stage 2 C) Stage 3 D) Stage 4
B) Stage 2 During stage 1, birth and death rates are both high (choice A is incorrect). During stage 2, the death rate falls while the birth rate remains constant (choice B is correct). During stage 3, the birth rate also decreases while the death rate stabilizes (choice C is incorrect). During stage 4, both the birth and death rate are low and population growth levels off (choice D is incorrect).
Researchers mutate all of the topoisomerases in a cell line. Which of the following is most likely to occur? A) Transcription of cell division genes increases B) The cell cannot replicate its DNA due to supercoiling C) An endonuclease is used to cleave the DNA and relieve supercoiling D) Translation is stalled
B) The cell cannot replicate its DNA due to supercoiling Topoisomerases relieve DNA supercoiling during DNA replication (choice B is correct). DNA replication, not transcription or translation, is affected in this situation (choices A and D are incorrect). An endonuclease cleaving the DNA would lead to widespread DNA damage and cell death (choice C is incorrect).
Researchers are studying the structure of a novel RNA enzyme. After making a G to C substitution at a single nucleotide position, they discover that the RNA enzyme loses its catalytic activity. However, the researchers then discover that a C to G mutation at a different location in the nucleic acid leads to a recovery of catalytic activity. Which of the following best describes this situation? A) The C to G mutation was important for catalytic activity. B) The double mutant enzyme's secondary structure restored the ability to carry out catalysis. C) A stop codon likely produced these mutations. D) The single nucleotide substitution was carried out by an endonuclease.
B) The double mutant enzyme's secondary structure restored the ability to carry out catalysis. RNA secondary structure is often studied by making mutations that compensate for other mutations. Here, the original enzyme likely contains a G-C bond that forms a secondary structure element. After the first mutation, however, the C-C pair no longer forms an interaction and the enzyme's conformation is changed. By introducing the second mutation, the C-G pair can produce the appropriate secondary structure needed to carry out catalysis (choice B is correct). Given that the enzyme was active before the C to G mutation, it is unlikely that this mutation was needed for catalysis (choice A is incorrect). A stop codon will affect proteins, and it is impossible to state that a stop codon created these nucleotide substitutions given the information in the text (choice C is incorrect). Endonucleases generally cleave DNA and don't create substitutions (choice D is incorrect).
Which of the following is NOT an assumption used for ideal gases? A) The molecules have no attraction or repulsion from one another B) The molecules undergo inelastic collisions C) Gases are made up of discrete, small particles called molecules D) The volume of the particles are small compared to the volume of the container
B) The molecules undergo inelastic collisions The molecules undergo elastic collisions, not inelastic collisions. Answer choices A, C, and D are assumptions that are made for ideal gases.
Which of the following terms represents the difference between the minimum and maximum volume of air in the lungs? A) Total lung capacity B) Vital capacity C) Residual volume D) Tidal volume
B) Vital capacity The difference between the minimum and maximum volume of air in the lungs is represented by the vital capacity (choice B is correct). Vital capacity is calculated by subtracting residual volume from total lung capacity (choices A and C are incorrect). Tidal volume is the volume of air exhaled or inhaled during the course of a normal, unstressed breath (choice D is incorrect).
Which of the following is the speed at which a single enzyme works? A) Vmax B) kcat C) Km D) IC50
B) kcat kcat is the turnover rate for a single enzyme, which is the speed at which a single enzyme works (choice B is correct). Vmax is the rate at which a concentration of enzymes works (choice A is incorrect). Km is the substrate concentration at ½ Vmax (choice C is incorrect). IC50 is often used to describe the concentration of inhibitor needed to inhibit 50% of an enzyme's activity (choice D is incorrect).
An African American student prepares for the SAT. On test day, he fills out the necessary forms including gender, race, age etc. During the exam, he finds that he is having more trouble remembering information he has read; he is continually returning to the passage for information. Ultimately, he earns a lower score. Which of the following explains this development? A. Self-fulfilling prophecy B. Stereotype Threat C. Fundamental Attribution Error D. Self-efficacy
B. (B) is correct, because the scenario in the question describes how stereotype threat works. The scenario in the questions works as follows: The student is primed for his racial identity by the test forms. He believes a negative stereotype about African Americans and intelligence exists. This threat of conforming to the stereotype causes the student to experience a reduced working memory. Stereotype threat refers to when an individual is in a situation where there is the chance of conforming to a stereotype and anxiety leads to the adherence to the stereotype. (C) refers to misattributing a behavior to a person's character rather than circumstances. This disagrees with the scenario and makes (C) incorrect. Self-efficacy is another way of describing self-confidence. This is not involved in the question. Therefore, (D) is incorrect. (A) is incorrect, because a self-fulfilling prophecy requires a conscious recognition of an outcome. This is not mentioned in the question and makes (A) incorrect.
A wooden box, whose top and bottom faces have twice the area as the 4 other faces, is being pushed across a floor at a constant speed. If the box is turned on any other side besides its top or bottom, what is the force required to push that box across the floor at the same speed? A. One-half the original force B. Equal to the original force C. Twice the original force D. Four times the original force
B. (B) is the correct answer. The force is proportional to the weight of the box, as well as the coefficient of kinetic friction. Excluded from this relationship is the surface area of the object in contact with the floor, therefore, the force is equal to the original one.
Reaction of methyl benzoate with LiAlH₄ can be expected to yield methanol and: A. phenol. B. benzyl alcohol. C. benzaldehyde. D. cyclohexanemethanol.
B. A strong reducing agent like LiAlH₄ will reduce an ester to two alcohols. In the case of methyl benzoate, the resulting alcohols are methanol and benzyl alcohol.
Which of the following would be least effective in rendering ATPase DnaK useless? A. Urea B. High concentration of Methane C. Acrylamide D. Very high temperature
B. ATPase DnaK is an enzyme, as can be seen by the 'ase' in the name. (B) is relatively inactive, and thus would be the worst in denaturing the protein. The three other options are all well-known denaturing agents, thus (B) is the correct answer.
According to the gate theory of pain, which of the following behaviors is most likely to be observed in participants attempting to alleviate pain in between trials? A. Placing their hands in hot water B. Rubbing their hands together C. Shaking their hands rigorously D. Placing their hands in their pockets
B. According to the gate theory of pain, the body prefers other signals from the touch modality (such as temperature or pressure) before pain. Rubbing the hands together provides just this kind of stimulus, and so choice B is the correct answer. While choices A and D might describe methods that participants might use to try to warm their hands in between trials, neither corresponds to the gate theory of pain.
Which of the following is the most likely explanation as to why an individual would perceive water to be cold before they perceive it to be painful? A. Nociceptors are activated far later than thermoreceptors within the sensory nerve. B. Signals from nociceptors must reach a certain limit before it is interpreted as pain. C. The individuals must perceive the water to be cold before they can sense the temperature. D. There are fewer nociceptors than thermoreceptors in the skin nerve cell.
B. According to the threshold theory of pain, the signal for pain is not interpreted as such until it crosses a certain minimum limit. Choice B applies this theory to nociceptors (pain receptors) and thus is the correct choice.
When action potential induces muscle contraction, which of the following occurs? A. Ca²⁺ is released into the cytosol; Ca²⁺ binds to tropomyosin B. Ca²⁺ is released into the cytosol; Ca²⁺ binds to troponin complex C. Ca²⁺ is pumped into the sarcoplasmic reticulum; Ca²⁺ binds to tropomyosin D. Ca²⁺ is pumped into the sarcoplasmic reticulum; Ca²⁺ binds to troponin complex
B. An action potential resulting in muscle contraction causes t-tubule depolarization, followed by SR release of Ca²⁺ in order for Ca²⁺ to bind to the troponin complex, thereby allowing tropomyosin to expose the myosin-binding sites on actin.
Which of the following is the best explanation for why animal fats (but not vegetable oils) are solid at room temperature? A. Animal fats have more double bonds than vegetable oils do. B. Animal fats have fewer double bonds than vegetable oils do. C. Animal fats have shorter fatty-acid tails than vegetable oils have. D. Animal fats have a lower concentration of sterols.
B. Animal fats are largely comprised of saturated triglycerides, which are solid at room temperature due to the presence of sigma bonds (not double bonds), as this allows for straight "packaging" or the molecules, which more easily forms a solid. Conversely, vegetable oils, which have double bonds as part of their structure, are not solid at room temperature, and this is due to the double bonds introducing "kinks" into the packaging system, so these fats are more fluid and thus not solid at room temperature.
How does water most likely react to polar protein groups? A. By not forming a solvation layer at all around any of the polar protein groups B. By forming a solvation layer to a lesser extent than around non-polar groups C. By forming a solvation layer to a greater extent than around non-polar groups D. By forming a solvation layer to an equal extent as that of the non-polar groups
B. Because the number of hydrogen bonds per unit of mass in water is greater than that of water with any polar group, as well as the fact that even the most polar groups have solubility limits, a solvation layer will form around even polar groups, though not to the extent that it does around non-polar groups because hydrogen bonding can still occur to a limited degree.
If an individual has a genetic mutation that blocks the development of bipolar cells, the individual will have difficulty with each of the following activities EXCEPT: A. driving a car. B. avoiding a hot stove. C. standing on one foot. D. noticing a gas leak.
B. Bipolar cells are found in the retina, nasal cavity, and inner ear, and relay sensory information relating to vision, olfaction, audition, and the vestibular sense. As a result, an individual lacking these cells, while being unable to see, hear, smell, or balance, would still be able to sense heat.
Which of the following hormones is associated with increased calcium deposit in the bone and decreased calcium concentration in the blood? A. Parathyroid hormone B. Calcitonin C. Thyroxine D. Glucagon
B. Calcitonin and parathyroid hormone, or PTH, are the two main hormones which act to regulate blood calcium levels. Among other functions, calcitonin inhibits the activity of osteoclasts which serve to break down bone matrix and release calcium into the blood. This contributes to the overall decreasing of calcium concentrations in the blood. Parathyroid hormone works by enhancing osteoclast activity, among other calcium-increasing functions for the blood.
Which of the following endocrine glands releases calcitonin? A. Hypothalamus B. Thyroid C. Parathyroid D. Pancreas
B. Calcitonin serves to counteract the function of parathyroid hormone which, as its name suggests, is released by the parathyroid. However, calcitonin is a peptide hormone released by the thyroid gland.
A student interested in myeloperoxidase (MPO), another enzyme used to fight pathogens, found that it functions best at a pH of 9 and a temperature of 37°C. Which of the following would be least likely to affect the enzyme's generation of harmful chlorine-containing chemicals? A. Adding more MPO B. Decreasing the amount of light C. Decreasing the pH to 8 D. Increasing the temperature to 40°C
B. Consider the different ways to affect enzyme activity. Temperature, pH, enzyme, and substrate amount all can affect it. Light is not an obvious way to affect rate, and thus choice B is the best answer.
Viruses can exploit the gap junctions found in certain types of tissue, mainly because of their close packing. Which of the following tissue types is most prone to this scenario? A. Nervous tissue B. Epithelial tissue C. Cardiac tissue D. Muscle tissue
B. Epithelial cells are known for tight packaging, and as such, they help form a protective barrier for our bodies. However, the same gap junctions that these cells use for nutrient exchange are also prone to viral spreading between cells.
Esterification of glycerol with a carboxylic acid could also be classified as: A. nucleophilic acyl substitution and a hydrolysis reaction. B. nucleophilic acyl substitution and a condensation reaction. C. electrophilic acyl substitution a hydrolysis reaction. D. electrophilic acyl substitution and a condensation reaction.
B. Esterification is a reaction that will substitute an -OH on a carboxylic acid for an -OR from some other molecule. This reaction requires attack on the carbonyl carbon, a slightly positive electrophilic species, by an oxygen on another molecule, a nucleophilic species, and is classified as nucleophilic acyl substitution since a nucleophile is attacking the carbonyl carbon and substituting itself for something else. Since the carboxylic acid is losing -OH and the glycerol is losing -H, a sum of H₂O is being lost, and this is called a condensation reaction.
If an exothermic reaction is heated, the equilibrium will shift in which direction? A. Towards the products B. Towards the reactants C. Neither D. It depends on the value of the individual k constants
B. Exothermic reactions can be written as A ↔ B + heat Based on Le Chatelier's Principle, we see that by adding heat, we will shift the equilibrium to the left - that is, towards the reactants.
According to Eysencks, personality difference arise mostly from: A. Environmental differences such as personality characteristics. B. Biological differences. C. Social and cultural differences. D. Factor analyses of personality differences.
B. Eysencks has also proposed that biological mechanisms underlie his three personality dimensions. Personality dimension is at the top of the hierarchy which are composed of specific traits, which in turn composed of automatic responses which are themselves based on a specific learned association between a stimulus and response.
A mutant chymotrypsin was constructed by changing serine-280 to aspartic acid. Serine-280 is in the pocket that recognizes the substrate specificity pocket, but does not participate in the cleavage reaction. Which of the following effects on chymotrypsin's catalysis would be most likely? A. Chymotrypsin would not catalyze any reactions due to disruption of its active site. B. Chymotrypsin would catalyze hydrolysis of peptides containing lysine or arginine more readily. C. There would be no change in catalysis because the effect was not at the active site. D. The enzyme would preferably catalyze peptide bond formation over peptide bond hydrolysis.
B. For this question, identify the amino acid types chymotrypsin hydrolyzes: nonpolar aromatic. If the side group is changed to a polar type, it will likely hydrolyze similar amino acids. Aspartic acid deprotonates to aspartate, an anion, which will bind well with positively charged side groups such as lysine and arginine. Choice A is incorrect because we cannot be certain that the active site is disrupted. Choice C is incorrect because the active site is not the only site that regulates protein function. Choice D is incorrect because we don't have sufficient information to conclude that the mutation would reverse the function of the enzyme.
Which of the following is true in rotational equilibrium? A. Velocity is zero B. Net torque is zero C. Net force is zero D. Angular momentum is zero
B. Forces on rotating systems are calculated as torques because the distance from the pivot affects the leverage on the system. This means that system can have two torques (F x d) - one torque with small force at large distance and the other torque with large force and small distance - and still be in rotational equilibrium because the two will cancel despite the forces not being equal. Hence the answer must be (B) to account for the effects distance has on the rotation.
Carboxylic acids can be formed by the I. Oxidation of alcohols II. Oxidation of aldehydes III. Reduction of ketones A. I and III only B. I and II only C. II and III only D. I, II, and III
B. Forming a carboxylic acid from an alcohol would involve the addition of an oxygen to the C-OH group which qualifies as oxidation. Forming a carboxylic acid from an aldehyde would involve adding an -OH to a CHO group which would also qualify as oxidation. Reduction of a ketone could involve either the removal of the oxygen from the carbonyl carbon or the addition of a hydrogen to the oxygen which would turn the ketone into an alcohol.
Which of the following is NOT true regarding the hormones synthesized in the adrenal cortex? A. The hormone and receptor complex binds directly to DNA to influence transcription. B. Binding to a receptor results in increased levels of cyclic AMP. C. The hormone is able to pass directly through the plasma membrane. D. The hormone is largely hydrophobic and requires a carrier protein.
B. Hormones synthesized in the adrenal cortex are all steroid hormones and thus exhibit the characteristics of this type hormones. The correct answer will likely not be true of steroid hormones. Peptide hormones bind to receptors anchored in the plasma membrane, causing a signaling cascade that involves second messengers.
In humans, which of the following does NOT contain bile? A. Liver B. Stomach C. Duodenum D. Gallbladder
B. Humans produce bile in the liver, and it is an important fluid for emulsifying fats. This bile can be drained directly into the duodenum (especially after eating), but is usually stored and concentrated in the gallbladder.
Protein-protein interactions are usually reversible and temporary. These interactions are mediated by a number of different mechanisms. Which of the following is NOT found in such temporary protein-protein interactions? I. Hydrophobic interactions II. Ionic bonds III. Covalent bonds A. I and II only B. III only C. I and III only D. I, II, and III
B. Hydrogen bonds, ionic bonds, and hydrophobic interactions are usually those that govern inter- and intra-protein interactions. Although proteins do not typically have hydrophobic areas exposed, many protein-protein interactions are governed by the hydrophobic interactions of the relevant amino acids. Hydrogen bonds are often found forming between the R-groups of amino acids as well as the peptide backbone. Ionic bonds are also often seen between positively- and negatively-charged amino acids. Only covalent bonds, whose energy is far higher and would prevent the proteins from easily dissociating, are not found in such protein-protein interactions.
Which of the following pieces of evidence would NOT support the hypothesis that mitochondria were once independent bacteria that eventually formed a symbiotic relationship with eukaryotic cells? A. Mitochondrial DNA is circular and not enclosed by a nuclear membrane. B. Mitochondrial ribosomes more closely resemble eukaryotic ribosomes than prokaryotic ribosomes. C. Many present-day bacteria live within eukaryotic cells, digesting nutrients that their hosts cannot and sharing the energy thus derived. D. Mitochondrial DNA codes for its own ribosomal RNA.
B. If mitochondria are believed to have been prokaryotic in origin, then any findings that reveal similarities between mitochondria and bacteria would support the hypothesis. The question asks which choice does NOT support the hypothesis. If choice B is true, and mitochondrial ribosomes more closely resemble those found in eukaryotes than those found in prokaryotes, then the hypothesis is not supported.
In the mixed-melting point analysis of an unknown sample, a pure standard of triphenylmethanol is added. If the unknown sample is in fact benzophenone, which of the following is the most likely result of the analysis? A. The melting point of the mixed samples will be higher than the melting point of the unknown alone. B. The melting point of the mixed samples will be lower than the melting point of the unknown alone. C. The melting point of the mixed samples will be the same as the melting point of the unknown alone. D. The melting point of the mixed samples cannot be predicted based on the information given.
B. Impurities cause melting points to decrease. Thus, since an impurity (triphenylmethanol) is added to the benzophenone, the melting point will be lower than the melting point of the unknown (benzophenone) alone.
Which of the following molecules that participate in the electron transport chain has the lowest affinity for electrons? A. Oxygen B. NAD⁺ C. Cytochrome C Oxidase D. Cytochrome C
B. In the electron transport chain, electrons move from molecules of low affinity to molecules of high affinity. Since oxygen is the final acceptor of electrons in the transport chain, we can see that it must be that oxygen has the highest electron affinity, and thus we can rule out (A). We know that NADH is the electron carrier that gives electrons to the electron chain and thus NAD⁺ must have the lowest electron affinity (since the electrons eventually move through cytochrome c and cytochrome c oxidase). Another way to think about this is that in the electron transport chain, NADH prefers to be NAD⁺ (i.e. it prefers to donate its electrons), and thus NAD⁺ has the lowest electron affinity since it favorably donates them to the other participants of the electron transport chain.
Which of the following is a likely explanation for the weight loss effect of increased insulin sensitivity? A. Increased insulin levels result in decreased weight gain and increased blood glucose utilization. B. Increased insulin sensitivity results in decreased weight gain and increased blood glucose utilization. C. Increased insulin sensitivity results in decreased gastric transit time and more efficient use of dietary nutrients. D. Increased insulin levels result in decreased fat deposition and decreased appetite.
B. Increased insulin sensitivity results in decreased fat deposition and more efficient use of glucose by insulin-dependent tissues.
Human placental lactogen often increases insulin resistance in pregnancy women. Which of the following lab abnormalities may be present in a woman as a result of this? A. Decreased blood glucose levels B. Increased blood glucose levels C. Decreased prolactin levels D. Increased prolactin levels
B. Insulin resistance is not a condition limited to pregnant women. The interaction between the receptor and insulin is inadequate to allow for sufficient uptake of glucose to the tissues in response to insulin. Thus, people with insulin resistance, regardless of the cause, should have higher levels of blood glucose.
Jean Piaget's stages of cognitive development, listed in order are: A. Sensorimotor, concrete operational, formal operational, and preoperational B. Sensorimotor, preoperational, concrete operational, and formal operational C. Preoperational, concrete operational, formal operational, and sensorimotor D. Formal operational, concrete operational, preoperational, and sensorimotor
B. Jean Piaget recognized four major stages of cognitive development. The sensorimotor stage is from birth to 2 years; the preoperational stage is from 2 to 7 years; the concrete operational stage is from 7 to 11 years; and the formal operational stage is from 11 years on.
The passage of large kidney stones typically causes blockage of passageways first in the A. Kidney B. Ureter C. Bladder D. Urethra
B. Kidney stones are formed in the kidney but are typically passed from the kidney through the ureter to the bladder, then excreted via the urethra. Large kidney stones will first cause passage problems in the ureter, since this is the first narrow passageway after exiting the kidney. Though they may cause blockage in the urethra as well, they are first a problem in the ureter.
Which of the following would be expected in a population of eukaryotic cells under low-oxygen stress? A. Increase in presence of oxidative radicals B. A higher pH in the mitochondrial intermembrane space C. Decrease in fermentation processes D. Upregulation of the Krebs cycle
B. Low-oxygen stress would negatively impact aerobic processes. In eukayrotic cells, this includes the ETC and the Krebs cycle, so we can eliminate (D). Oxidative radicals should decrease under low-oxygen conditions, making (A) incorrect. (C) is incorrect since fermentation is used to overcome low-oxygen conditions, so we would expect an increase. The answer is (B) because the decrease in oxygen negatively impacts the ability of the ETC to pump protons into the intermembrane space, resulting in a lower H+ concentration and therefore an increase in the pH.
Which of the following would NOT enhance phagocytosis by macrophages? A. Clumping of microbes B. Decreased phagocyte surface receptors C. The binding of antibodies to the surface of microbes D. Increased concentration of peroxides inside lysosomes
B. Macrophages are crucial for the phagocytic response. A complex system of signals is initiated by contact with a microbe, and this results in a form of specialized endocytosis. After encountering a microbe, the macrophage will ingest it (occurs inside a vesicle called a phagosome). Following this, it utilizes its enzymes and peroxides (inside its lysosomes) for digestion.
A molecule with 0 chiral centers can only have which of the following? A. A diastereomer B. A conformational isomer C. An enantiomer D. An epimer
B. Molecules with 0 chiral centers are unable to have diastereomers, enantiomers, or epimers because these definitions require at least a single stereocenter within the molecule. Conformational isomers, however, refer to different conformations with respect to rotations around single bonds and exist within molecules without stereocenters. Thus (B) is correct.
Rank the following elements in increasing order of their reactivity with fluorine. I. Potassium II. Calcium III. Iron A. I < II < III B. III < II < I C. I < III < II D. III < I < II
B. One of the general rules for reactivity is the likelihood of an electron exchange. This would correlate with a large difference in electronegativities. Thus, the most electropositive of the three elements should react most strongly with fluorine, while the most electronegative will react most weakly. Since potassium is furthest to the left on the periodic table, we know it is the most electropositive. Iron, being the furthest right of the three elements, will be the least reactive. This makes the correct order of reactivities III < II < I, or (B).
Which of the following is not a step in polymerase chain reaction (PCR)? A. Addition of a DNA polymerase B. Addition of restriction enzymes to cleave DNA C. Applying heat to denature the DNA D. Lowering of temperature to allow annealing of primers to DNA
B. PCR reaction does not require restriction enzymes (which are enzymes that cut DNA) to function. PCR essentially requires applying heat to denature the DNA, then decreasing the temperature to allow primers to bind, then slightly increasing the temperature to allow for extension of the DNA strand. Thus (B) is the correct answer.
A blood sample is taken from a sick patient and the sample is lysed. Out of the total lysate, peptidoglycan is detected. The patient has most likely been infected with which of the following? A. Protist B. Bacteria C. Fungus D. Parasitic worm
B. Peptidoglycan is a key feature of many bacterial cell membranes and is only produced by bacteria. Therefore, if a test comes back positive for peptidoglycan, it can be reliably concluded that bacteria are present in the sample.
Which of the following does NOT contradict the Second Law of Thermodynamics? A. When throwing two dice, throwing a two is more probable than throwing a seven. B. In photosynthesis, glucose molecules are produced from water and carbon dioxide. C. A heat engine in a vehicle produces 500 J of heat that does 500 J of work. D. A refrigerated compartment is cooled by an adjacent freezer compartment.
B. Photosynthesis does indeed require an expenditure of energy: as it occurs in an open system, which can exchange energy with its surroundings, energy from the sun is used to drive photosynthetic reactions. The efficiency of photosynthesis is never 100%, so some energy is lost (i.e. not all the energy goes into creating order from disorder). Since the overall entropy of the universe increases, there is no contradiction of the Second Law of Thermodynamics. The wrong answer choices all violate or contradict the Second Law of Thermodynamics. When throwing two dice, it is more likely that a seven will be thrown than a two, because there are more ways to throw a seven than a two - the entropy of a seven is higher than that of a two, and systems in nature will tend towards states of higher entropy. A heat engine can never operate with 100% efficiency (converting all of the heat produced into useful work) exactly because of the Second Law of Thermodynamics: there is always some heat loss to the environment. Finally, heat energy will never flow spontaneously from a cooler object to a warmer one (which is what choice D says).
A positive charge moves in the positive x direction in a magnetic field pointing in the negative y direction. What is the direction of the force on the object? A. Positive z direction B. Negative z direction C. Clockwise around the direction of motion D. Counterclockwise around the direction of motion
B. Recall the right hand rule. Assembling the plane of x and y on a table, when the charge moves in the positive x direction with the magnetic field in the negative y direction, the direction of force is down into the table. This is the negative z direction.
If she has been good about going to the gym the previous week, a woman rewards herself with a bubble bath on Sunday night. She also rewards herself for every 20-lb weight loss by buying new clothes in a smaller size, and finds that she is more likely to exercise consistently when she treats herself to new clothes rather than to a bubble bath. Which of the following is true for her regarding the effectiveness of her exercise reinforcement schedules? A. Fixed ratio is more effective than variable ratio. B. Fixed ratio is more effective than fixed interval. C. Variable interval is more effective than fixed interval. D. Variable ratio is more effective than variable interval.
B. Rewarding herself on a fixed interval schedule once per week is not as effective as rewarding herself on a fixed ratio schedule for number of pounds lost. If she shops occasionally once she has exercised enough to fit into a smaller size, she is on a variable ratio schedule. If she shops every three months after exercising consistently, she is on a variable interval schedule.
Which of the following reactions necessarily inverts the stereochemistry of the compound? I. SN1 reaction II. SN2 reaction III. E2 elimination A. I only B. II only C. I and II D. I and III
B. SN1 reactions produce racemic mixtures, because they involve the complete removal of the leaving group before the nucleophilic attack, which can be from any position and can thus invert or retain the stereochemistry. SN2 reactions, on the other hand, involve nucleophilic attack and attachment before the complete dissociation of the leaving group. This results in the nucleophile attack always coming from the opposite side of the leaving group, inverting the stereochemistry. E2 reactions involve the loss of a leaving group without replacement by a nucleophile. Typically this results in the formation of a double bond as a replacement of the leaving group. There is no inversion of stereochemistry in such reactions.
Antifreeze proteins are produced by certain organisms to help protect their cells against damage from ice crystals. These proteins evolved independently in a variety of different species in accordance with multiple historical ice ages. Such evolution is an example of: A. Divergent evolution B. Convergent evolution C. Parallel evolution D. None of the above
B. Since a diverse set of species evolved to a single trait (i.e. converged on one trait), this is an example of convergent evolution. This would be an example of parallel evolution only if the traits evolved from closely-related species.
A particular solution of a concentrated acid has a pH of 2. The water is evaporated until half the volume remains, leaving the acid twice as concentrated. What has happened to the pH of the solution? A. The pH is equal to or below 1. B. The pH is between 1 and 2. C. The pH remains at 2. D. The pH is between 2 and 4.
B. Since pH = -log[H⁺], if the concentration of H⁺ doubles, the effect on the log is less than a full point (i.e. a pH of 1 is 10 times more concentrated than a pH of 2). Although the pH will drop, it will not drop to a level as low as 1, and will therefore be between 1 and 2 (B).
Given two hoses, with Hose A having a diameter 50% larger than Hose B. The two hoses are connected (one after the other) from a source of water, and there is no leaking. Through which section of the total hose does water flow the fastest? A. The Hose A section B. The Hose B section C. The flow is the same in either section D. The faster flow rate depends on the order of the Hose A and Hose B sections
B. Since the question states that there is no leaking, the volume of water (per unit of time) going through each hose section is the same. The volume per unit time is also equal to the flow speed per cross sectional area. Since the cross sectional area is smaller in the Hose B section, it will require a faster flow speed of water in order to get the same volume per unit time as in the Hose A section
What type of system is a thermometer? A. Open system B. Closed system C. Isolated system D. Complex system
B. Since the thermometer responds to changes in the temperature of its environment with volumetric expansion, it must be capable of exchanging heat energy. Thus, it is not an isolated system. Since thermometers are expected to be reusable, and the contents are often toxic in some way, there is no exchange of matter between the thermometer and the environment. A system which exchanges energy but not matter with its surroundings is a closed system. An open system exchanges matter with the surroundings, while an isolated system does not exchange energy with its surroundings.
Which of the wollowing processes will NOT result in the formation of butanoic acid? A. The reaction of butanol with potassium permanganate followed by acidification B. The reaction of butylmagnesium chloride with carbon dioxide followed by acidification C. The reaction of sodium butanoate with aqueous mineral acid D. The reaction of propylmagnesium chloride with carbon dioxide followed by acidification
B. Since this is a NOT question, each method must be evaluated for its product. Butanol with potassium permanganate would result in butanoic acid, eliminating choice A. Butylmagnesium chloride mixed with carbon dioxide will produce a butane with CO₂ attached, which would be pentanoic acid, so this will NOT produce butanoic acid. Sodium butanoate mixed with aqueous mineral acid would replace the sodium with a proton and thus would turn butanoate into butanoic acid, eliminating choice C. Propyl magnesium chloride mixed with CO₂ would add a CO₂H to a propane, which would be butanoic acid, eliminating choice D.
Which of the following is best associated with steroid hormones? A. Steroid hormones are water-soluble B. The effects of steroid hormones are mediated by binding to a soluble receptor protein C. Steroid hormones are synthesized directly from amino acid precursors D. The intracellular actions of steroid hormones are mediated by small peptides
B. Steroid hormones are lipid hormones that can be grouped by the receptors to which they bind, and steroid hormone receptors are generally soluble proteins. Steroid hormones are not water soluble, but they are soluble in lipids, and can easily pass through cellular and nuclear membranes. Because steroids and sterols are lipid-soluble, they can diffuse freely from the blood through the cell membrane and into the cytoplasm. Non-steroid hormones, which are water-soluble (and typically peptide hormones), cannot do this, and must act through membrane bound receptors and intracellular second messenger systems to exert their effects.
The steroid hormones produced by the smooth endoplasmic reticulum would be stored in which of the following ways? A. Peroxisomes, so the hormones could aid in lipid breakdown. B. Steroid hormones are not stored; because they are lipophilic they are able to diffuse through lipid bilayers. C. Secretory vesicles, so the hormones could be released when needed. D. Lysosomes, so the hormone could aid in the breakdown and destruction of excess secretory products.
B. Steroid hormones are made from cholesterol as lipid derivatives; they cannot be stored by lipid bilayers. Since secretory vesicles, peroxisomes, and lysosomes are membrane bound, they cannot store steroids. It should be noted that peptide hormones are stored in secretory vesicles.
Which of the following is responsible for the regulation of TSH secretion? A. Negative feedback exerted by thyroid hormone at the hypothalamus B. Negative feedback exerted by thyroid hormone on both the pituitary and hypothalamus C. Positive feedback exerted at the level of the pituitary on the thyroid and parathyroid D. Positive feedback exerted at the level of the hypothalamus on the parathyroid and adrenal glands
B. TSH is secreted by the pituitary gland in response to TSH secreted by the hypothalamus. TSH, however, has two levels of control. Thyroid hormone exerts negative feedback on the hypothalamus, while also exerting negative feedback at the pituitary. This results in very tight control of thyroid hormone.
Flame atomic absorption spectroscopy (AAS) is a technique used to convert free atoms into their gaseous state and measure the absorption of light. This technique follows the Beer-Lambert law, meaning it is most useful for which of the following? A. Determining the identity of an unknown element in a sample. B. Determining the concentration of a solution. C. Identifying the decomposition rate of the element in the solution. D. Finding the relative solubility of the atom in different solutions.
B. The Beer-Lambert law, or A = ε/c is used to determine the concentration of a solution. (A) is incorrect because the technique only measures the absorbance of the light; one must have a standard and know the identity of the analyte to be able to use AAS. (C) is incorrect because elements will not "decompose" in solution. (D) is incorrect because there is no testing involving multiple solutions.
The Gram stain distinguishes what type of organisms? A. Pathogenic bacteria versus nonpathogenic bacteria. B. Bacteria with a single membrane and a thick layer of peptidoglycan versus bacteria with two membranes and a thin layer of peptidoglycan. C. Bacteria with a cell wall versus bacteria without a cell wall. D. Bacteria versus archaea.
B. The Gram stain (Gram positive vs. Gram negative) allows visual discernment of bacteria that either retain crystal violet or do not. Bacteria retaining crystal violet have very thick layers of peptidoglycan and a single membrane while bacteria that do not retain crystal violet but retain the counterstain safranin generally have an outer membrane along with the plasma membrane and thin layers of peptidoglycan. Certain cells will stain Gram negative despite not having these parameters, but nonetheless the Gram stain is intended to distinguish between these types of bacteria.
What happens to the air in a diver's lungs as he dives down 20 m beneath the ocean surface? A. The internal energy of the gas in his lungs decreases. B The internal energy of the gas in his lungs increases. C. the gas in his lungs loses heat to the ocean. D. The work done by the gas in his lungs is positive.
B. The air in a diver's lungs is compressed adiabatically as they dive. This means that heat is not lost or gained since the body acts as an insulator. For adiabatic processes, ∆U = -W, where W is the work done by the gas. Here, the gas is having work done on it (it's being compressed) so W < 0. This means that ∆U > 0, and so the internal energy of the gas in his lungs increases.
Which of the following functional groups produces the strongest acid? A. Alkene B. Carboxylic group C. Alcohol D. Alkyne
B. The ascending order of acidity of the functional groups is: Alkene < alkyne < alcohol < carboxylic acid. The carboxylic acid is the strongest acid because it's conjugate base is the most stable given that stabilizing effect of the resonance can occur between the two oxygens of the deprotonated carboxylic group. Thus the answer is (B).
Which of the following statements is true regarding mitosis cell division? A. A mitotic division of a diploid cell produces two haploid cells. B. Mitosis begins where there is sufficient mitosis promoting factor (MPF) during the G₂ growth phase. C. All somatic cells undergo mitosis. D. Mitosis is divided into two stages, mitosis I and mitosis II.
B. The correct answer and statement is (B). Mitosis begins after the G2 checkpoint is passed, which requires a minimum level of MPF. (A) is false because mitosis results in two identical cells from one parent cell. (C) is false because some somatic cells such as mature neural and muscle cells are in an arrested growth state that does not involve cell division. (D) is false, meiosis involves two divisions (producing haploid cells from a diploid cell), while mitosis involves one division.
The rough endoplasmic reticulum is so named because of ribosomes on its membrane. Which of the following statements best describes the way in which these ribosomes translate proteins? A. From the cytosol, into the intermembrane space of the endoplasmic reticulum B. From the cytosol, into the lumen of the endoplasmic reticulum C. From the intermembrane space of the endoplasmic reticulum, into the cytosol D. From the lumen of the endoplasmic reticulum, into the cytosol
B. The endoplasmic reticulum does not have an intermembrane space, thus A and C are false. Ribosomes attached to the membrane of the endoplasmic reticulum translate proteins directly into the lumen of the endoplasmic reticulum through porins. Recall that mRNA does not enter the lumen of the endoplasmic reticulum; it remains in the cytosol, thus, proteins will be translated from the cytosol into the lumen.
A block of ice is reduced in temperature from -5°C to -10°C. As a consequence, which of the following is true? A. The entropy of the block of ice has increased. B. The total entropy of the universe has increased. C. The temperature of the air surrounding the block of ice has decreased. D. The average kinetic energy per molecule of the water has increased.
B. The entropy of the block of ice has not increased, it has decreased (the ice gets colder). Therefore, choice A is incorrect. However, the universe must pay the price for the decrease in entropy in the ice: since the process isn't reversible, the entropy of the universe must increase. Choice C is incorrect because it is unclear how the block was cooled (the temperature of the air surrounding the block could have either increased or decreased; we cannot be certain). Choice D is incorrect because the average kinetic energy per molecule of the ice (the temperature of the ice) has decreased.
Many antipsychotic medications cause galactorrhea, or inappropriate lactation. Which of the following hormones is likely suppressed by antipsychotic medications? A. Serotonin B. Dopamine C. Estrogen D. Human placental estrogen
B. The hormone that is mainly responsible for lactation is prolactin. Prolactin is produced and released by the anterior pituitary gland. However, prolactin production is regulated by the hypothalamus. Under normal, non-lactating circumstances, the hypothalamus releases dopamine, known in this context as prolactin inhibiting factor. Dopamine suppresses the production of prolactin. Thus, if a drug suppresses dopamine production or binding, then prolactin will be released, and lactation will occur.
The deamination of alanine produces a carbon compound which then enters the Citric Acid Cycle. What is the identity of this carbon compound? A. Succinate B. Acetyl-CoA C. Malate D. Fumarate
B. The important part of this question revolves around knowing what compound feeds into the Citric Acid Cycle (acetyl-CoA). The Citric Acid Cycle consumes acetate (in the form of acetyl-CoA) and water, reduces NAD⁺ to NADH (which then goes into oxidative phosphorylation), and then produces carbon dioxide. Certain deaminated amino acids (deaminated alanine, cysteine, glycine, serine, and threonine) are converted to pyruvate and can either enter the citric acid cycle as oxaloacetate or as acetyl-CoA.
Which of the following has the greatest first ionization energy? A. Na B. Mg C. K D. Ca
B. The ionization energy (IE) is the energy required to remove an electron from an atom. On the periodic table, IE generally increases going from bottom to top and from left to right. Thus Mg and Ca both have higher ionization energies than Na and K, and Mg has a higher ionization energy than Ca.
Which of the following gives rise to the skeletal system? A. Notochord B. Mesoderm C. Endoderm D. Ectoderm
B. The mesoderm gives rise to muscles, connective tissue (blood, bone, adipose), and circulatory and part of the renal system. Endoderm gives rise to the major organs. Ectoderm gives rise to the nervous system and the skin.
An individual is diagnosed as having a defect in their organ of Corti. Which of the following impacts would be expected? A. Inability to balance B. Hearing loss C. Vertigo (or the perception of constant spinning) D. Poor color vision but appropriate night vision
B. The organ of Corti is responsible for transducing sound that comes into the ear into electrical signals which can be sent to the brain. Clearly, a defect in this structure would result in hearing loss. Thus (B) is the correct answer. (A) and (C) would result from defects in the vestibular system, which is unrelated to the organ of Corti. (D) is related to vision.
As non-polar protein groups cluster in water, the water experiences a(n): A. decrease in entropy. B. increase in entropy. C. decrease in hydrogen-bonding. D. increase in the solvation layer.
B. The organization of the solvation layer causes a decrease in entropy, so the clustering of non-polar groups, by virtue of diminishing the layer, causes a favorable increase in entropy. In fact, this increase in entropy is the predominant thermodynamic influence resulting in the clustering of nonpolar groups in polar sovlents like water.
A spring in simple harmonic motion is synchronized with the motion of a pendulum. The masses on the spring and the pendulum are identical. If the masses on the ends are doubled, what will happen to the synchronization? A. The pendulum will have a period that is greater than that of the spring. B. The pendulum will have a period that is less than that of the spring. C. The period of the spring will decrease. D. The period of the pendulum will increase.
B. The period of an oscillating spring is directly dependent upon the mass while the period of an oscillating pendulum is independent of the mass. Therefore when the mass is doubled, the period of the spring will increase while the period of the pendulum remains the same. Thus the period of the pendulum will be less than that of the spring making (B) the correct answer and also explaining why (A), (C), and (D) are incorrect.
Which one of the following endocrine systems is involved in the establishment and maintenance of human circadian rhythms? A. Pituitary gland B. Pineal gland C. Pancreas D. Thyroid gland
B. The pineal gland is a small endocrine gland in the brain which produces the hormone melatonin, which in turn affects the sleep patterns in circadian rhythms. Information on the length of the day and night is taken from the retina and passed along to the pineal gland, which secretes melatonin (which peaks at night). While some studies have shown that the pineal gland influences the pituitary gland's secretion of certain sex hormones, the main hormones secreted from the pituitary gland are involved in growth, blood pressure, sex organ function, and metabolism, among others.
An alternative method for keeping the tea hot would be to place the teapot on a 10-pound bock that has been heated in an oven to 300°C. A block of which of the following substances would best be able to keep the tea hot? A. copper (specific heat = 0.39 J/g•K) B. granite (specific heat = 0.79 J/g•K) C. iron (specific heat = 0.45 J/g•K) D. pewter (specific heat = 0.17 J/g•K)
B. The question is asking which substance can transfer large amounts of heat to the tea as they reach thermal equilibrium. The substance with the highest specific heat (granite) is the one that can transfer the most heat to the tea and teapot per degree drop in its own temperature.
In the diagram below, given the pKa of -OH1 is 8.24 and the pKa of -OH2 is 7.81, determine which of the following will be most abundant in solution at a pH of 8.00. (protonated = OH, deprotonated = O⁻) A. OH1: protonated, OH2: protonated B. OH1: protonated, OH2: deprotonated C. OH1: deprotonated, OH2: protonated D. OH1: deprotonated, OH2: deprotonated
B. The relevant concept being tested here is the relationship between pH and pKa. Of course, your ability to interpret whether a diagram shows a protonated or deprotonated hydroxyl is also being tested. Recall that when the pH is below the pKa of a titratable group, the group will be predominantly protonated (more detail found at the end of this explanation). An easy way to think about this is that a low pH has a high concentration of H+ (protons), which will tend to protonate titratable groups. At higher pH, there are fewer protons in solution and they will dissociate from the titratable groups. When the pH = pKa, we expect the protonated/deprotonated states to be equal. So, looking at our two titratable groups on the compound, we can see that at pH 8.00, the pH is lower than the pKa for -OH1 while it is higher than the pKa for -OH2. Thus we expect -OH1 to be protonated, and -OH2 to be deprotonated. This corresponds to diagram II. Note that all of these compounds will be in solution to some degree, but the most abundant will be II. More detail: Basic groups, like amino groups, have high pKas, whereas acidic groups like carboxylic acids have low pKas (recall that Ka = [A-][H+]/[HA]; therefore an acidic group which favors dissociation ([A-][H+]) will have a higher Ka. The pKa is the -logKa, so a higher Ka will result in a lower pKa (do the math to compare the pKas of high and low Ka values).
A step in the lab procedure for a protein analysis involves placing cytoplasmic protein in a hydrocarbon (e.g. hexane). Which of the following would most likely NOT happen next? A. The protein would fold itself into a different conformation B. The protein would retain the conformation it had prior to entering the hydrocarbon solution C. The polar side-groups would orient themselves away from hydrocarbon D. The nonpolar side-groups would interact with the hydrocarbon molecules via Van der Waals interactions
B. The step involves placing a protein in a hydrocarbon (hexane), which is nonpolar. By doing so, this will cause any polar side-groups in the protein to shield themselves away from the nonpolar environment, while the nonpolar side-groups are free to interact with the hydrocarbon environment. This reaction of the polar side-groups in the protein will likely result in a different conformation of the protein, such as the polar groups facing inward in a micelle-like fashion to avoid the nonpolar environment.
Which style of Parent-Child attachment would most likely be seen with a child who is described as "emotionally distant?" A. Secure attachment B. Avoidant attachment C. Anxious/ambivalent attachment D. Disorganized attachment
B. The step involves placing a protein in a hydrocarbon (hexane), which is nonpolar. By doing so, this will cause any polar side-groups in the protein to shield themselves away from the nonpolar environment, while the nonpolar side-groups are free to interact with the hydrocarbon environment. This reaction of the polar side-groups in the protein will likely result in a different conformation of the protein, such as the polar groups facing inward in a micelle-like fashion to avoid the nonpolar environment.
Which of the following mechanisms for hormonal regulation is exemplified by oxytocin during childbirth? A. Negative feedback B. Positive feedback C. Partial agonism D. Hormonal antagonism
B. The two main mechanisms for hormonal regulation are negative and positive feedback. In a negative feedback system, the product of the pathway suppresses a step or steps earlier in the pathway. In the presence of excess end product, the pathway is suppressed. In positive feedback, the pathway is stimulated by the end product, such that the pathway will continue unabated until some end point is reached. In childbirth, this endpoint is the expulsion of the infant and the placenta. Most hormonal regulation in the body is governed by negative feedback. Oxytocin is one of the few hormones that is regulated by positive feedback.
1 mg/kg is identical to which of the following? A. 1 mM B. 1 ppm C. 1 N D. 1 mmol
B. There are 1000 mg in 1 g and 1000 g in 1 kg, meaning there are 1,000,000 mg in 1 kg, meaning the units of 1 mg/kg are the same as 1 ppm. This is a simple conversion that you should be comfortable doing on the MCAT. Units of mM give mmol/L which are not the same as mg/kg. Units of Newtons are also not the same as mg/kg.
Which of the following is an inaccuracy regarding peptide bonds and polypeptide structure? A. Polypeptides are formed through a condensation reaction between two amino acids. B. At times, the peptide bond is composed of disulfide bond, as in the case of cysteine. C. Peptide bonds with a polypeptide are broken through a hydrolysis reaction. D. The carboxyl-carbon on one amino acid acts as the electrophile the hydrolysis reaction.
B. This question requires a fairly in-depth understanding of peptide bonds and their formation. They form through a condensation reaction (i.e. water is released as a product). In the reaction, the ammonia group acts as a nucleophile and attacks the carboxyl-carbon. (B) is an incorrect statement because peptide bonds are NEVER composed of disulfide bonds. Disulfide bonds form between the chain groups of amino acids and are very distinct from peptide bonds.
In the acidic conditions of the stomach, pepsin optimally works and is able to catalyze the breakdown of proteins into amino acids. Which of the following is the most plausible effect that pH has on the enzyme? A. Low pH causes the glutamic acid residue in the allosteric site to stay protonated and enhance binding. B. The histidine residue is protonated in the active site and binds anionic residues more effectively at lower pH. C. Low pH results in deprotonation of the active site environment and increases substrate affinity. D. The glycine side chain in the active site donates a proton and binds positive charges on the substrate better.
B. To answer this question, consider where the substrate binds on the enzyme. The active site, and not the allosteric site (choice A), is the key to catalysis. Choice C is incorrect because low pH means more acidic, meaning protonation. Choice D is incorrect because glycine's side chain is a hydrogen, which does not dissociate.
At what point in the circuit is the total resistance highest? A. Just before blood enters the pump B. Just after blood enters the body C. Within pre-capillary arterioles D. Within post-capillary venules
B. Total resistance is related to cross-sectional area and the flexibility of the vessel. Arteries, which have a muscular layer, are less flexible than veins, and thus have a higher resistance. As blood moves away from the heart, the total cross-sectional area increases. Therefore, an artery close to the heart will have the highest resistance. Blood enters the body at the aorta, a large artery, and will thus experience the greatest resistance at this point.
In which orbital(s) would you expect to find the valence electrons of In? A. 5s only B. 5s and 5p only C. 5s, 4d, and 5p D. 5s, 5d, and 5p
B. Valence electrons are those on the outermost energy levels for non-transition metals. Since the d orbitals for a given period are always n-1 (e.g. the 4th period fills the 3d orbital; the 5th period fills the 4d orbital), only the s and p orbitals are considered valence. Since In is not a transition metal and has electrons in both the 5s and the 5p orbitals, these and only these would be its valence electrons.
Which of the following best describes viruses? A. Obligate extracellular parasites B. Obligate intracellular parasites C. Facultative extracellular parasites D. Facultative intracellular parasites
B. Viruses require a host cell in order to complete their life cycle - hence, they are intracellular parasites. Because they are unable to replicate, hence "live" outside of their host, they are considered obligate intracellular parasites rather than facultative intracellular parasites.
Which of the following immune cells is primarily responsible for producing specific antibodies? A) Dendritic cells B) T-lymphocytes C) B-lymphocytes D) Mast cells
C) B-lymphocytes B-lymphocytes are the antibody-producing cells in the body. Dendritic cells are involved in antigen presentation (choice A is incorrect). T-lymphocytes are involved in modulating the immune response (T-helper) or killing infected cells (T-cytotoxic) (choice B is incorrect). Mast cells are filled with granules and release histamine, which leads to inflammation (choice D is incorrect).
Researchers want to determine whether or not proteins interact, and they identify a potential dimerization interface in one of the proteins. Which of the following is a method by which the researchers could confirm the two proteins interact with one another? A) Thin layer chromatography B) DNA sequencing C) Co-immunoprecipitation D) Northern blot
C) Co-immunoprecipitation The MCAT likes to test students on experimental techniques and passages. Co-immunoprecipitation is a common technique used to identify an interaction between two proteins (choice C is correct). Thin layer chromatography is often used in organic chemistry to test the progress of a reaction (choice A is incorrect). DNA sequencing and Northern blots deal with nucleic acids, not protein (choices B and D are incorrect).
Several members of a recycling-based non-profit board decide to meet to discuss introducing recycling to a city that does not currently recycle. Most members agree that recycling should be optional during the first year. After the meeting, however, they decide to push for mandatory recycling at each house, water limits, and solar panels during the first year. This is an example of: A) Social facilitation B) Groupthink C) Group polarization D) Peer pressure
C) Group polarization Group polarization occurs when the individuals in a group come to a more extreme decision than any individual member would have made alone. Here, we see that the group members become much stricter with their recycling measures after the meeting (choice C is correct). Social facilitation describes the tendency of an individual to perform a simple task better when other people are around (choice A is incorrect). Groupthink occurs when individuals in a group come to an uncreative solution in favor of minimizing conflict (choice B is incorrect). Peer pressure occurs when peers without the authority to change a person's behavior cause the person to behave in a certain way (choice D is incorrect).
Researchers carry out a reaction and determine the presence of two products. Product 1 both forms and degrades quickly whereas product 2 both forms and degrades slowly. Which of the following best describes the product 1 and product 2, respectively? A) Kinetic, kinetic B) Thermodynamic, thermodynamic C) Kinetic, thermodynamic D) Thermodynamic, kinetic
C) Kinetic, thermodynamic Kinetic products form more quickly but are less stable whereas thermodynamic products form more slowly but have greater stability.
Which of the following is the ideal gas law? A) PE = mgh B) F = ma C) PV = nRT D) V = IR
C) PV = nRT PV = nRT is the ideal gas law (choice C is correct). PE = mgh is the equation for gravitational potential energy (choice A is incorrect). Newton's second law states that force is equal to mass multiple by acceleration (choice B is incorrect). V = IR is Ohm's Law for circuits (choice D is incorrect).
Which of the following amino acids is most likely to engage in pi-stacking interactions with adenosine? A) Serine B) Proline C) Phenylalanine D) Arginine
C) Phenylalanine Phenylalanine contains a conjugated aromatic ring, so it is the most likely to engage in pi-stacking interactions with an adenosine nucleotide. Serine, proline, and arginine are not aromatic, so they are unlikely to engage in pi-stacking interactions (choices A, B, and D are incorrect).
Which of the following best describes why protic solvents decrease nucleophilicity? A) Protic solvents are too sterically bulky and prevent the nucleophile from contacting the electrophile. B) Protic solvents alter the chemical properties of the electrophile to decrease the reaction efficiency. C) Protic solvents can hydrogen bond with the nucleophile, thereby decreasing the frequency of nucleophilic attack. D) Protic solvents introduce a net positive charge to the nucleophile and decrease nucleophilicity.
C) Protic solvents can hydrogen bond with the nucleophile, thereby decreasing the frequency of nucleophilic attack. By forming hydrogen bonds with protic solvents, nucleophiles cannot move as freely in solution and it is harder for them to attack electrophiles (choice C is correct). Protic solvents are not necessarily sterically bulky; water is an example of a protic solvent (choice A is incorrect). The question asks how protic solvents affect then nucleophile, not the electrophile (choice B is incorrect). While protic solvents might make the nucleophile less negative, they are highly unlikely to introduce a positive charge to the nucleophile (choice D is incorrect).
A researcher wants to measure the amount of a proto-oncogene mRNA in mice cells. Which of the following is the best method to measure mRNA expression levels? A) Western blot B) Native protein gel C) RT-qPCR D) Molecular cloning
C) RT-qPCR RT-qPCR is used to measure the expression of mRNA products in a cell (choice C is correct). Western blots are used to measure protein levels in a sample (choice A is incorrect). A native protein gel provides information about protein, not mRNA (choice B is incorrect). Molecular cloning is a tool used for a variety of molecular biology assays, but it is not directly used to measure the expression of cellular mRNA (choice D is incorrect).
Which of the following agents is the LEAST likely to be mutagenic? A) UV rays B) Oxygen C) Salt D) Alkylative agent
C) Salt Salt is unlikely to be mutagenic and actually stabilizes DNA (choice C is correct). UV rays, oxygen (in the form of reactive oxygen species), and alkylative agents are likely to cause DNA damage (choices A, B, and D are incorrect).
A student about to walk the stage for graduation is convinced that she will accidentally trip. As soon as she receives her diploma, she trips and falls on the stage. This is an example of: A) Looking-glass self B) Stereotype threat C) Self-fulfilling prophecy D) Fundamental attribution error
C) Self-fulfilling prophecy The self-fulfilling prophecy concepts occurs when an individual expects a certain outcome, and their behavior subconsciously leads to that outcome (choice C is correct). The looking-glass self concept states that individuals behave based on how they think others perceive them, but the question stem does not state that the student is thinking about how others perceive her (choice A is incorrect). Stereotype threat describes the phenomenon in which stereotyped individuals conform to stereotypes about themselves. Here, there is no indication that the student was fulfilling a stereotype (choice B is incorrect). Fundamental attribution error describes the tendency to assume dispositional attributions instead of situational attributions. Here, there is no information about what the audience thinks of her fall (choice D is incorrect).
Increasing which of the following parameters would increase the rate constant of a reaction? A) Activation energy B) Reactant concentration C) Temperature D) Product concentration
C) Temperature The rate constant of a reaction is given by the following equation: k = Ae-Ea/RT. So, by increasing activation energy, the rate constant of the reaction actually decreases (choice A is incorrect). The concentrations of reactants and products do not show up in this equation (choices B and D are incorrect). The equation shows that by increasing temperature, the rate constant of the reaction is also increased (choice C is correct).
Which of the following best describes medicalization? A) The process by which an individual becomes a doctor B) The situation in which a doctor treats another doctor C) The increasing definition of human issues as medical conditions D) The increasing access to healthcare in rural locations
C) The increasing definition of human issues as medical conditions Medicalization describes the increasing number of human issues that are defined and treated as medical conditions (choice C is correct; choices A, B, and D are incorrect).
Which of the following are crossed during a test cross? A) Unknown genotype with homozygous dominant B) Unknown genotype with heterozygote C) Unknown genotype with homozygous recessive D) Unknown genotype with unknown genotype
C) Unknown genotype with homozygous recessive The goal of a test cross is to determine an unknown genotype. By crossing the unknown genotype with a homozygous recessive organism, it is possible to know if the unknown genotype is homozygous dominant (all offspring will have dominant phenotype), heterozygous (offspring will have both dominant and recessive phenotype), or homozygous recessive (all offspring will have recessive phenotype) (choice C is correct; choices A, B, and D are incorrect).
A student postulated that the change in transcriptional profiles for K27M histone H3.3 variant-containing cells might be due to the loss of an epigenetically regulated lysine. Is this hypothesis reasonable? A) No; not all lysines in histones are regulated. B) No; methionine can receive the same modifications that lysine receives. C) Yes; lysines are important sites of epigenetic regulation in histones. D) Yes; histone lysines directly interact with RNA polymerase to increase transcription.
C) Yes; lysines are important sites of epigenetic regulation in histones. Lysines are important sites of regulation in histones, especially for lysine acetylation, which opens up the chromatin to make it accessible for transcription (choice C is correct). There are many more factors at play, such as post-translational modifications, promoters, and enhancers that lead to RNA polymerase recruitment and transcription (choice D is incorrect). Just because all lysines may not be regulated does not mean that lysines are not important and may not play a role in this specific case (choice A is incorrect). Methionine cannot receive the same modifications that lysine receives (choice B is incorrect).
A student states that thermodynamic products are more energetically stable than kinetic products. Is this statement correct? A) No; kinetic products form much more quickly than thermodynamic products. B) No; kinetic products sample more conformations due to their speed and can therefore arrive at a lower energy state. C) Yes; thermodynamic products form more slowly but achieve a greater level of stability. D) Yes; thermodynamic products require a lower temperature to find a stable form.
C) Yes; thermodynamic products form more slowly but achieve a greater level of stability. The statement made by the student is true: thermodynamic products are more energetically stable than kinetic products (choices A and B are incorrect). Thermodynamic products form more slowly, but they are more stable and achieve a lower energy state (choice C is correct). Thermodynamic products actually require a higher energy to find a stable form because they often have a greater activation energy needed in order to form the lower energy state. As a result, they require a higher temperature. A lower temperature will favor the kinetic products (choice D is incorrect).
The boiling point of methane is 110 K while the boiling point of germane, GeH₄, is 185 K. This difference in boiling points is primarily attributable to which of the following? A. The difference in electronegativity between carbon and germanium. B. The difference in polarity of the bonds between C-H and Ge-H. C. The difference in size between carbon and germanium. D. The difference in ionization energy between carbon and germanium.
C. (A) and (B) are false because although there is a difference in electronegativity between the two elements (and therefore a difference in the polarity of their bonds), both molecules are perfectly tetrahedral in structure and therefore will not have any axis of asymmetry in terms of polarity, i.e. they are both nonpolar. (D) is false because ionization energy of an element would not directly impact its contribution to the boiling point of a compound. (C) is the correct answer because van der Waals are in part influenced by the size of molecules with larger molecules having stronger van der Waals forces and therefore higher boiling points.
Which of the following is FALSE regarding isomers and chirality? A. Diastereomers cannot also be enantiomers B. A carbon with a double bond to another carbon atom could form TWO isomers C. Any amino acid is a chiral molecule D. Enantiomers are non-superimposable mirror images of each other
C. (C) is an incorrect statement (and thus the correct answer) since not every amino acid has an asymmetric carbon atom; glycine is actually an exception and doesn't have an asymmetric carbon atom. (A) is correct because diastereomers - by definition - are not enantiomers. (B) is correct because the situation is describing the E,Z stereoisomers, which differ based on the orientation of the carbon atoms sharing the double bond. Lastly, (D) is correct, with a common example being as one's left and right hands, which are the same except for opposite orientation.
Given a mirror or lens, assume that a "real" image is on the same side as the object. "Virtual" refers to the other side of the lens/mirror that is "inside" the lens or mirror. Given this nomenclature, for an object in focus, a concave mirror makes a: A. Real, upright image B. Virtual, upright image C. Real, inverted image D. Virtual, inverted image
C. A convex mirror would produce (B). A concave mirror produces an image that is on the same side as the actual object. The image will appear upside-down. Thus, the image would be real and inverted. The correct answer is (C). Note that this holds for objects beyond the focal point of the mirror. For objects closer than the focal point, the same is not true; the image is virtual and upright instead.
A hormone is noted to traverse the cellular membrane to bind to a receptor within the nucleus. Which of the following hormones is least similar to the hormone in question? A. Estrogen B. Progesterone C. Prolactin D. Aldosterone
C. A hormone that binds to a receptor in the ucleus must be able to pass through the plasma membrane. This is a characteristic of a steroid hormone. Thus, the correct answer will be a hormone that is not a steroid. Choices A, B, and D are all steroid hormones and therefore started off as a cholesterol ring.
When two amino acids react to form a peptide bond: A. an amide is formed by electrophilic acyl substitution. B. a lactam is formed by nucleophilic acyl substitution. C. an amide is formed by nucleophilic acyl substitution. D. a lactam is formed by electrophilic acyl substitution.
C. A peptide bond is formed when the carboxylic acid from one amino acid connects to the amine group on another amino acid. When a carboxylic acid and an amine react, they form an amide, eliminating B and D. This process where the -OH group of the carboxylic acid is substituted for another molecule is known as nucleophilic acyl substitution.
What is the average voltage for alternating current (AC)? A. >0 V B. <0 V C. 0 V D. The voltage relates to the device attached to the circuit
C. Alternating current is such that it oscillates however achieves the same magnitude in the positive and negative directions. This sinusoidal pattern averages to a voltage of 0 V, thus (C) is the correct answer.
An object is placed on a scale and its weight is recorded. How would the recorded weight of the object change as the atmospheric pressure was increased? A. The recorded weight would increase because the air density increases as pressure increases. B. The recorded weight would increase because air density decreases as pressure increases. C. The recorded weight would decrease because the air density increases as pressure increases. D. The recorded weight would decrease because the air density decreases as pressure increases.
C. As pressure increases on a gas, its density increases accordingly. The increased density provides greater buoyant force on the object. Thus the object's apparent weight would decrease as its buoyant force increases.
Signal transduction describes the process of extracellular signalling molecules and ligands binding to cell-surface receptors which triggers events inside the cell. Which of the following best describes an event NOT typically associated with signal transduction started by extracellular signals? A. The binding of epinephrine to adrenergic receptors B. Protein phosphorylation C. A steroid hormone binding to its receptor D. Activation of secondary messenger molecules
C. Besides Choice C, all other choices involve an aspect of signal transduction started via extracellular signalling (such as epinephrine). Nuclear receptors are intracellular receptors which typically have steroid hormones (e.g. testosterone) as their ligands. Steroid receptors are a subsection of nuclear receptors and are located primarily within the cytosol. As such, Choice C stands out from the others based on the fact it will very likely involve passage through the nuclear membrane and into the nucleus to accomplish its goal (e.g. gene transcription, protein production).
Which of the following is LEAST likely to impact the boiling point of a solvent? A. The number of hydrogen bonds it can form B. The molecular weight of the molecule C. The presence of d-orbitals in any of its atoms D. The presence of charged species on the atom
C. Charges and hydrogen bonds would directly impact the attractive forces of the molecule, which would have an impact on the boiling point. For (B), molecular weight is often tied to London dispersion forces which will also impact boiling point. The correct answer is (C) because the presence of d-orbitals is irrelevant to the consideration of boiling point, as d-orbitals are not valence shells and will not impact intermolecular forces.
Acetic acid is the common name for ethanoic acid. Acetic acid is a product of all of the following reactions except: A. treating ethanol with potassium permanganate. B. hydrolysis of ethanoic anhydride. C. decarboxylation of 3-oxobutanoic acid. D. treatment of sodium acetate with HCl.
C. Choice A is a standard oxidation of a primary alcohol by KMnO₄ and will produce a carboxylic acid with two carbons, or acetic acid. Hydrolyzing the bond at the center oxygen of ethanoic anhydride will release two ehtanoic acids, eliminating choice B. In choice C, decarboxylation is occurring on a β-keto acid, which will lose CO₂ and form propanone.
During which of Piaget's stages in his cognitive development model does a child typically learn Conservation? A. Sensorimotor B. Preoperational C. Concrete operational D. Formal operational
C. Conservation is a hallmark ability that is mastered during the Concrete Operational stage (7-11 yrs old).
Which of the following correctly describes a polar covalent bond? A. Involves a transfer of electrons to the atom of less electronegativity B. Involves equal sharing of an electron pair between two atoms C. Involves unequal sharing of an electron pair between two atoms D. Results in the formation of oppositely charged ions
C. Covalent bond implies sharing of electrons, and polar means there is a difference in electronegativity, so one atom is "pulling" more strongly on those shared electrons, thus there is unequal sharing.
How would a decrease in the pH of a solution affect the volatility of decanoic acid? A. The volatility decreases until the pH equals the pKa at which point the volatility increases. B. The volatility increases until the pH equals the pKa at which point the volatility decreases. C. The volatility continues to increase as the pH decreases. D. The volatility continues to decrease as the pH decreases.
C. Decanoic acid is a relatively small molecule that is also relatively nonpolar as long as it is protonated. Thus its volatility should be highest when the pH is lowest since it is most protonated when the pH is lowest. The pKa is not a relevant threshold for the volatility since this trend continues as the pH declines. Thus the correct answer is (C).
A cart is moving toward a hill that is 50 m tall. The cart coasts up the hill but does not reach the top, missing the peak by only a few meters. After rolling back down, the driver doubles the weight of the cart in an attempt to double the momentum and make it over the hill. Which of the following is the most likely result of this strategy, assuming the same velocity is used as in the first attempt? Note: neglect friction and air resistance. A. The cart will reach the top but not make it over the hill B. The cart will reach the top and make it over the hill C. The cart will reach the same spot it reached before D. The cart will not reach as far as it reached before
C. Doubling the momentum is not a relevant consideration here. What is important is the forms of energy; kinetic energy is being converted to gravitational potential energy. We have a conversion from ½mv² to mgh, and therefore we can see that the masses cancel. That is, mass is not relevant to the conversion of the two forms of energy. This explains why two objects of different masses will fall at the same rate, neglecting air resistance. Since the velocities are the same, the height reached will be the same, making (C) the correct answer.
Hyperpolarization is a phenomena seen in neurons after an action potential. This occurs due to A. The rush of sodium out of the neuron B. The rush of sodium into the neuron C. The rush of potassium out of the neuron D. The rush of potassium into the neuron
C. During an action potential in a neuron, initially, the sodium gates open and sodium rushes into the cell. This results in a depolarization of the cell. When this occurs, potassium channels begin to open as sodium channels close, which results in a rush of potassium out of cell, hyperpolarizing the neuron.
Which of the following CANNOT be determined for a 3.5 mol sample of H₂ gas at 307 K and 750.05 mmHg? A. The volume of the gas B. The internal energy of the gas C. The heat energy required to attain 307 K and 750.06 mmHg D. The amount of work done in isobarically compressing to 0.1 L
C. Given several state functions for a gas, it is generally possible to calculate the value of other state functions. Internal energy is a state function which is dependent on temperature, while volume is a state function dependent on density and mass (if the identity of the gas is known, the density can be looked up), or on pressure, temperature, and number of moles. Therefore, choices A and B can be determined, and so can be eliminated. Furthermore, some process functions can also be determined, if the process is sufficiently restrictive. Since isobaric compressions are constrained, the work done can be calculated solely based on the initial and final volumes. By contrast, the amount of heat required or work done in order to attain a particular state vary in relation both to one another and to the starting state.
Which of the following derangements of hormones would be expected in hypothyroidism caused by the pituitary dysfunction? A. Low TSH, high T₃ and T₄ B. High TSH, low T₃ and T₄ C. Low TSH, low T₃ and T₄ D. High TSH, high T₃ and T₄
C. Hypothyroidism is signified by low blood levels of T₃ and T₄. Identifying the cause of hypothyroidism requires analysis of the TSH levels. If TSH levels are high, this signifies appropriate pituitary function. However, if TSH is low and T₃ and T₄ are also low, this indicates that the problem is likely due to inadequate pituitary function. Choice D would be the hormone profile of hyperthyroidism due to a pituitary cause.
The Hill plot is useful for determining the level of cooperativity in proteins such as hemoglobin. The slope of the Hill plot, or Hill coefficient, describes the degree of cooperativity. If it is 1, ligand binding is not cooperative. If it is greater than 1, there is positive cooperativity. Which of the following situations describes a situation in which the coefficient could be less than 1? A. Binding of a substrate to the active site of an enzyme causes breakdown into 2 product molecules. B. Myoglobin has only 1 subunit and is unable to demonstrate cooperativity. C. Binding of a substrate to one subunit of a multisubunit protein decreases the affinity of other sites for the ligand. D. Hemoglobin has 4 subunits, which each affect the affinity of the other.
C. If a coefficient > 1 indicates positive cooperativity then a coeffcient < 1 indicates negative cooperativity, in which ligand binding impedes further ligand binding at other sites. Choice C is therefore correct as it shows decreased affinity as more things are bound.
A particular gas is placed in a cathode ray and energy is ran through the tube in the form of an electric current. A bright orange light can be seen once current is provided. Which of the following explains the phenomenon observed? A. Electrons of the gas become excited, which eventually results in the release of an electron with energy in the spectrum of visible light B. Gas molecules are excited and oscillate at a frequency in the visible light spectrum C. Photons are released after the excitation of electrons in the individual gas atoms D. Gas molecules absorb the energy and convert it into visible light through energy transfer within the nucleus
C. In this scenario, gas molecules do absorb the energy from the electric current through electron movement into higher energy states. When the electrons drop back down to their normal energy levels (as is seen in fluorescence and other types of luminescence), energy is released in the form of a photon, therefore (C) is the correct answer.
An iron nail was immersed in a solution of copper sulfate and when it was removed from the solution, it was coated with a layer of copper metal. After a different iron nail was immersed in a solution of zinc nitrate and removed, this nail rusted just as rapidly as a new iron nail. Rank these three metals in order of activity from most active to least active. A. Zn > Cu > Fe B. Fe > Cu > Zn C. Zn > Fe > Cu D. Cu > Fe > Zn
C. Iron replaced copper from the solution because it was able to lose electrons more readily than copper. The iron lost electrons and was oxidized and the copper gained electrons and was reduced. Iron is thus more active than copper. The iron nail that was immersed in the zinc nitrate rusted as fast as normal which means it was not galvanized (coated with zinc). Therefore the iron did not lose any electrons to the zinc and was not oxidized. Zinc is thus more active than iron.
The amino acid glycine is much more likely to be conserved in protein structures than is aspartic acid. Which of the following statements is most likely to explain this discrepancy? A. The lack of chirality is important for many biological reactions. B. Glycine's large R group creates more van der Waals interactions with other amino acids. C. The size of glycine allows for more extensive protein interactions via turns. D. Aspartic acid's hydrophobicity repels water molecules and other amino acids.
C. It is difficult to predict the answer to this question, but the correct answer should explain why glycine is more likely to be conserved in protein structures than aspartic acid. Glycine is unique in that it is the smallest amino acid, and therefore is useful in regions where space is restricted. Chirality, not a lack of it (choice A), is important in biological reactions. Choice B is incorrect because glycine does not have a large R group. Choice D is incorrect because aspartic acid is not hydrophobic.
Ketogenesis is a metabolic process where ketone bodies are produced as a result of fatty acid breakdown. In humans, high levels of ketogenesis would most likely occur at which point? A. Before the depletion of glycogen stores B. Concurrently with the depletion of glycogen stores C. Immediately after glycogen store depletion D. Only in times of metabolic crisis in conjunction with protein degradation for energy production
C. Large scale fatty acid breakdown occurs after the stores of glycogen have been depleted, because glycogen is a readily-available source of energy for the body. This makes (A) and (B) incorrect. After the depletion of fatty acids (i.e. during starvation), the body will begin to degrade proteins and consume them for energy, at which point ketogenesis will largely be complete since the fats have been consumed. This makes (D) incorrect, leaving (C) as the correct answer.
What is the main biological reason for why hemoglobin is the main oxygen transport protein in the blood as opposed to myoglobin? A. Hemoglobin binds oxygen tighter than myoglobin, making it a more successful protein for oxygen transport. B. Myoglobin acts as an allosteric enzyme, making it less preferable for oxygen transport. C. Myoglobin binds oxygen much tighter than hemoglobin, increasing efficiency of transport when hemoglobin is the oxygen transport protein. D. Myoglobin is structurally incapable of successful travel through the blood stream.
C. Myoglobin binds oxygen tighter than hemoglobin, thus hemoglobin travels with the oxygen, and then is able to release it to cells because the myoglobin (which is the oxygen storage device of cells) is able to out-compete hemoglobin for the oxygen, and thus oxygen is successfully delivered to the body. Myoglobin is not an allosteric enzyme, thus B is wrong. D is clearly wrong because hemoglobin is a tetramer of four proteins, all which very closely resembe myoglobin.
Paclitaxel is most likely to hamper which phase of mitosis? A. Prophase B. Metaphase C. Anaphase D. Telophase
C. Paclitaxel stabilizes tubulin polymers once they form. Thus, it becomes harder for them to shorten. Tubulin polymers shorten during anaphase, when the chromosomes are pulled towards the two poles of the cell. Thus, the correct answer is choice C.
The third harmonic of a standing wave between two walls has a wavelength of 1.5 m. What is the distance between the walls? A. 0.5 m B. 1.5 m C. 2.25 m D. 4.5 m
C. Recall that the equation for harmonic series between two fixed points is D = nλ/2 where n is the harmonic, λ is the distance between the wavelength, and D is the distance between the walls. Thus, if the wavelength is 1.5 m for the third harmonic, the distance must be 3(1.5)/2 = 2.25 m
The intermediate step of reduction of nonanoic acid by LAH (lithium aluminum hydride) involves the formation of: A. nonanol. B. octanal. C. nonanal. D. decanol.
C. Reduction from lithium aluminum hydride involves going through an aldehyde intermediate after nucleophilic attack by hydride on the carbonyl. This will preserve the number of carbons but turn the carboxylic acid into an aldehyde.
Gloria grew up in Hungary, in a neighborhood she refers to as the Jewish Ghetto. Everyone in her neighborhood was Jewish and all of the businesses were owned by Jewish families. This is an example of: A. Racism B. Exclusionism C. Residential segregation D. Collectivism
C. Residential segregation is the separation of one group from another into different neighborhoods. Residential segregation can be based on race, ethnicity, religion, or socioeconomic status. Residential segregation is officially illegal in the United States, but minority groups are often segregated as the result of economic circumstances or personal preference.
A 0.01 M solution of HCl would have a pH of approximately 2. For HF, which has a Ka lower than that of HCl, a 0.01 M solution would have a pH that would be: A. less than 2. B. equal to 2. C. greater than 2. D. The answer cannot be determined from the given information.
C. Since HF has a lower Ka, that tells us it is a weaker acid (it will have a higher pKa). Therefore we know that the concentration of hydronium ions of an HF solution will be less than an equally-concentrated HCl solution and will thus have a higher pH.
Which of the following particles has the greatest momentum when traveling at 99% the speed of light? A. β⁻ particle B. A neutron C. An α particle D. β⁺ particle
C. Since momentum is the product of mass and velocity, the particle with the most momentum will be the particle with the most mass when the velocity is constant. α particles are composed of two neutrons and two protons and have much more mass than β⁻ particles, neutrons, or β⁺ particles.
Pharmaceutical drugs are often listed as being provided in HCl salt form. These drugs have HCl added to increase the drug solubility by: A. protonating a carboxyl group. B. dehydrating an alcohol. C. protonating an amine group. D. hydrogenating an alkene group.
C. Solubility of organic compounds can be most easily increased by protonation/deprotonation of groups to cause them to become charged. This forms salts which are far more soluble in water than uncharged molecules. Since HCl is being added to the drug, this is a protonation event. Protonation of an amine would cause it to become an ammonium cation which is soluble in water. Carboxyl groups and alcohols can have their solubilities increased by deprotonation rather than protonation.
Diols have higher boiling points than their corresponding alcohols with only one hydroxyl group because diols: A. can self-associate to form hydrogen bonds. B. dissociate more easily in solution. C. can form intermolecular bonds on both ends of the molecule rather than just one. D. lack positive charges.
C. Some diols can self-associate if the carbon chain is long enough, but this is not true of all diols and it is not relevant to their boiling point. Boiling point is affected by the intermolecular forces, so hydrogen bonds within the same molecule would have negligible impact. Alcohols do not dissociate readily in solution, and diols are no exception, so (B) does not explain the higher boiling point of diols. Although it is true that diols lack positive charges, this has no bearing on whether or not they have higher boiling points, making (D) incorrect. (C) is the correct answer because of the increased ability of diols to form hydrogen bonds with one another, strengthening their intermolecular forces and thus increasing their boiling point.
A gas bubble is located at the bottom of a water-filled container. As the bubble is rising toward the surface, which of the following occurs? Assume the gas does not dissolve into the water. A. The bubble becomes smaller. B. The water level rises. C. The bubble becomes larger. D. The water level lowers.
C. The amount of gas in the bubble remains constant, since none will dissolve into the water. As the bubble rises through the water, the external pressure on the bubble decreases according to Pressure = ρgh where ρ is the density of the water. Thus, as the bubble rises, the volume increases as the ratio of the internal pressure to external pressure increases. The correct answer is (C).
Which of the following processes would NOT occur in response to reduced blood insulin levels? A. Decreased uptake of blood glucose by muscle cells B. Increased conversion of glycogen into muscle glucose C. Increased utilization of glucose as fuel D. Increased utilization of fatty acid as fuel
C. The answer to this question must be a process that does not occur when insulin levels are low. Insulin levels are reduced at times of low blood glucose concentration in order to conserve glucose for the use by the brain. Thus when insulin levels fall, tissues such as muscle and liver decrease glucose uptake and utilization (choice A) and start using fatty acids instead (choice D). When insulin levels are low, glucagon levels rise by default and promote conversion of glycogen into glucose (choice B) to maintain blood glucose levels. The only processes that don't occur in response to low insulin levels is choice C, increased utilization of glucose as fuel.
The GTP used by tubulin could come directly from the products of: A. glycolysis. B. the pentose phosphate pathway. C. the citric acid cycle. D. oxidative phosphorylation.
C. The citric acid cycle directly produces GTP.
Which provides the correct order in which sound waves travel through the ear (from the outside)? A. Round window, cochlea, tympanum, oval window B. Incus, malleus, stapes, oval window C. Eardrum, incus, oval window, cochlea D. Cochlea, malleus, round window, stapes
C. The correct answer is (C). The order through which sound waves travel through the ear from the outside is: eardrum (tympanum) -> malleus -> incus -> stapes -> oval window -> cochlea -> round window.
The density of a gas in a closed container will increase if: A. The temperature of the gas increases under constant pressure B. The pressure of the gas decreases under constant temperature C. The pressure of the gas increases under constant temperature D. The number of moles of the gas decreases
C. The density of a gas is mass / volume. In this closed container, due to the inverse relationship between pressure and volume, if the pressure increases (with temperature held constant), this will consequently decrease the volume. Since volume makes up the denominator of the density relationship (mass / volume), a smaller volume will therefore increase the density of the gas.
The density of a gas in a closed container will increase if: A. the temperature of the gas increases under constant pressure. B. the pressure of the gas decreases under constant temperature. C. the pressure of the gas increases under constant temperature. D. the number of moles of the gas decreases.
C. The density of a gas is mass / volume. In this closed container, due to the inverse relationship between pressure and volume, if the pressure increases (with temperature held constant), this will consequently decrease the volume. Since volume makes up the denominator of the density relationship (mass / volume), a smaller volume will therefore increase the density of the gas.
A student is experimenting with a spring and wants to launch an object attached to the spring at 10 m/s. The spring is compressed and the object, with a mass of 1 kg, is placed at the end of the spring for launch. If the spring constant is 2500 N/m, how much does the spring need to be compressed to launch the object at the desired velocity? A. 0.2 cm B. 5 cm C. 20 cm D. 25 cm
C. The desired velocity is 10 m/s and we know the mass is 1 kg. The kinetic energy of the object, therefore, will be KE = ½mv² = ½(1)(10²) = 50 J. The equation to relate energy, spring constant, and displacement is the spring potential energy equation PE = ½kx². We know all parameters except for x, so 50 = ½(2500)x² or 1/25 = x² which means x = 1/5 m or 20 cm.
Which of the following would NOT support the chemiosmotic-based model of oxidative phosphorylation? A. The transfer of electrons through the electron transport chain results in the formation of a proton gradient across the inner mitochondrial membrane B. Oxidative phosphorylation cannot occur in cells with breached mitochondrial membranes C. Raising the pH of the fluid in the intermembrane space results in ATP synthesis D. The order of the enzyme complexes in the electron transport chain results in proton flow in one direction
C. The direction an ion moves across a membrane by active transport (or diffusion) is determined by an electrochemical gradient. In mitochondria, proton gradients are used to generate a chemiosmotic potential (also known as a proton motive force) that is used for the synthesis of ATP by oxidative phosphorylation. Because the movement of these ions (in this case, hydrogen ions across a membrane) are down their electrochemical gradient, this is known as chemiosmotic, and it plays a crucial role in cellular respiration. Choices A, B, and D support this chemiosmotic-based model of oxidative phosphorylation, because a proton gradient is formed and because the overall phosphorylation process does not happen when the membranes are ruptured (thus, they are crucial for setting up the ionic difference between both sides of the membrane). Choice C would NOT support this model because it states ATP synthesis is a result of a pH change, not a result of ion movement (and proton gradient formation), which form the basis of ATP synthesis via oxidative phosphorylation.
Multicopy inhibition is a regulatory mechanism that limits the expression of the transposase gene by blocking: A. replication. B. transcription. C. translation. D. post-transcriptional modification.
C. The net result of multicopy inhibition is that IN RNA is not allowed to attach to a ribosome. Ribosomes are the site of protein synthesis, or translation, and consist of a small subunit and a large subunit. Translation is initiated by the binding of an mRNA transcript to the small ribosomal subunit. Therefore, if mRNA is not allowed to attach to a ribosome, translation cannot occur. Hence, multicopy inhibition must repress translation, and C is the correct answer.
A bacterium is being studied by a scientist who discovers that oxygen is lethal to the bacterium. Which of the following best explains the reason for this? A. The ATP produced by the organism's metabolism from exposure to oxygen floods the cell to overdose. B. The oxygen is consumed by oxygen-detecting metabolic reactions which induce bacterial suicide. C. The bacterium lacks enzymes for catalyzing reactive oxygen species into more benign compounds. D. The normal energy-producing reactions of the bacterium are outcompeted by the presence of oxygen and the cell is no longer able to produce energy.
C. The organism being described is an obligate anaerobe - that is, an organism which requires anaerobic conditions to survive. This is due to the fact that such organisms lack the proper enzymes to adequately deal with reactive oxygen species (like superoxide dismutase), which can quickly oxidize proteins and nucleic acids beyond repair. (A) is incorrect because the cell would not be able to use oxygen in the first place; (B) is incorrect because we have no information in the prompt to suggest this is true and there is no such mechanism known which is relevant to the MCAT; (D) is incorrect because, like (A), the cell would be unable to use oxygen and it would not outcompete normal energy-producing metabolic reactions.
The identity of a pancreatic tumor can often be determined by the hormone levels found in a blood sample. Which of the following cell types is likely to be involved if blood levels of somatostatin are high? A. Alpha cells B. Beta cells C. Delta cells D. Gamma cells
C. The pancreas secretes three main endocrine hormones: glucagon, insulin, and somatostatin. Alpha cells secrete glucagon, beta cells secrete insulin, delta cells secrete somatostatin, and there are no gamma cells in the pancreas. Thus, a tumor that secretes somatostatin must involve delta cells.
During a cycle, the entropy state of the water in the steam engine: A. steadily increases. B. steadily decreases. C. increases then decreases. D. decreases then increases.
C. The water that powers the steam engine is first in a liquid state where it is progressively heated to form steam, or water vapor. Steam is gaseous, and therefore has higher entropy than the liquid water. Once allowed to enter the piston chamber, the steam sees an increase in available positions, and thus continues to increase in entropy. However, as the steam cools, it condenses, returning to a liquid state as it exists the piston chambers with a corresponding decrease in energy.
A student has crystallized a compound and is concerned there may be an impurity. The presence of the impurity can be most easily determined by which of the following techniques? A. Fractional distillation B. Rotary evaporation C. Melting point analysis D. Thin layer chromatography
C. Thin layer chromatography is often a good way to look for multiple compounds, but its major downfalls are a) it requires large concentrations of each and substance to be present and would not work for minor impurities and b) it requires that each compound has sufficiently different physical properties as to visibly separate. Rotary evaporation and fractional distillation will help to separate two compounds but in this case would not work well for solids nor would they be helpful in determining whether there is an impurity. Mixed-melting point analyses are often used to determine purity of samples due to freezing point depression; presence of an impurity lowers the melting point and can therefore be easily determined.
Biogas is produced by placing a sample of grass and bacteria in an adiabatic calorimeter. Assuming the biogas acts like an ideal gas, when the biogas is compressed in the calorimeter, it experiences: A. a decrease in temperature and an increase in internal energy. B. a decrease in temperature and a decrease in internal energy. C. an increase in temperature and an increase in internal energy. D. no change in either the temperature or internal energy.
C. This question relates to the First Law of Thermodynamics, ∆U = Q - W (work done by the system). If the compression of the gas is adiabatic, that means that Q = 0, so ∆U = -W. Since the system is compressed, work is done on (not by) the system, and is therefore negative. Since W is negative, -W is positive, and so choices B and D can be eliminated. Next, an increase in internal energy increases the temperature (the average kinetic energy of the gas molecules), so choice C is correct.
Muscle fibers come in two generic types: fast twitch and slow twitch. Fast twitch fibers contract quickly and fatigue quickly as well - they rely mainly on glycolytic mechanisms for energy production. Slow twitch muscle relies upon aerobic activity for energy. Which of the following metabolytes would not be expected to be produced in fast twitch muscle metabolism? A. Pyruvate B. ADP C. CO2 D. 1,3-bisphosphoglycerate
C. This question requires you to know the various intermediates of glycolysis. Carbon dioxide is the only compound which does not appear anywhere in the glycolytic pathway. Carbon dioxide is produced during aerobic respiration, and thus we would expect to find it in slow twitch, but NOT fast twitch muscle.
In glycolysis, as the concentration of fructose 6-phosphate increases, PFK activity increases and more fructose 2,6-biphosphate (F-2,6-BP) is produced. Which of the following would occur in the presence of increased insulin levels? A. Insulin attempts to lower blood glucose levels by increasing the activity of fructose biphosphatase 2. B. Insulin inhibits glucagon activity and thus decreases glycolysis as a whole. C. Insulin leads to stimulation of PFK-2, increasing F-2,6-BP and enhancing the feedforward pathway. D. Insulin stimulates breakdown of F-2,6-BP and acts as a negative feedback mechanism.
C. To answer this question, consider the relationship between insulin and glycolysis. Insulin lowers blood glucose levels by having cells uptake glucose where it can be broken down via glycolysis. Thus, it should act to increase the feedforward system employed by fructose 6-phosphate, F-2,6-BP, and PFK-2.
Which of the following statements about carboxylic acids is NOT true? A. The boiling point of propionic acid is lower than that of caproic acid. B. The boiling point of oxalic acid is higher than that of methanoic acid. C. The pKa of 2-methylbenzoic acid is higher than that of caproic acid. D. The pKa of dichloroethanoic acid is lower than that of propionic acid.
C. To evaluate the statements methodically, first deal with boiling point, which is largely affected by intermolecular bonds. With carboxylic acids, those acids with higher boiling points are the ones with the longer chains and the greater ability to hydrogen-bond. Therefore, the statements in choices A and B are true. Next, evaluate pKa: relative acidity of an acid can be judged by the stability of the conjugate base of that acid. Since dichloroethanoate is stabilized by induction, it is a stronger acid (with a lower pKa) than propionic acid and the statement in choice D is true. The resonance of the benzoic acid also contributes to it being acidic and therefore should have a lower pKa than caproic acid.
Protein glycosylation in eukaryotic proteins is associated with which organelle? A. Mitochondria B. Nucleus C. Golgi apparatus D. Ribosome
C. Translation of proteins is done by ribosomes which may be associated with the endoplasmic reticulum. However, these structures are primarily involved with the translation of proteins. Processing of proteins occurs later; in particular, glycosylation is typically performed by the endoplasmic reticulum and the Golgi apparatus.
Researchers conduct a study of depression in 100 teens. On the instrument used to measure depression, scores may range from 0-20, with higher scores indicating greater symptomatology. A score of 5 is recommended as the diagnostic cutoff. This distribution has a mean of 5, a standard deviation of 2, and a median of 4. Which of the following is NOT true for the sample? A. More than a third of participants are mildly-to-moderately depressed. B. More than half of the participants are depression-free. C. Over half of the participants meet the diagnostic cutoff for depression. D. Multiple participants are severely depressed.
C. Under the given distribution, roughly 34% of participants scored between 5 and 7, above the cutoff score but towards the low end, indicating mild to moderate depression. The mean is higher than the median, indicating that high scores of a few severely depressed individuals skew the distribution and pull the mean upward away from the median. Half the participants are below the median of 4 as the median is the middle score. Given a cutoff score of 5, with 50% scoring under 4, more than half of the participants must be depression-free, so the correct answer is (C) as it would be impossible for over half of the participants to have scored above the cutoff of 5.
If Sally can bounce 5 m in the air on a trampoline, how fast is she going when she reaches the trampoline? Assume g = 10 m/s² A. 4 m/s B. 7 m/s C. 10 m/s D. Cannot be determined from the given information.
C. We can calculate this answer using mgh = ½mv². Quickly we can see that her mass is cancels out, leaving us with gh = v²/2; v = √(2gh). When she is at a height of 5 meters, 100% of her energy is potential, whereas when she is just reaching the trampoline, all of her energy is kinetic. Thus we can use 5 m*10 m/s²*2 = 100. √100 = 10.
At immense pressures, hydrogen undergoes a phase transition to a unique state. In this state, the space between hydrogen atoms is less than their Bohr radius, meaning electron clouds overlap significantly. This overlap explains which of the following phenomena of this state of hydrogen? A. Its lack of a triple point with any other state of hydrogen B. Its density being lower than at STP C. Its ability to conduct electricity D. Its lack of color
C. We cannot determine its color by looking at its density or Bohr radius, so (D) is incorrect. We also cannot infer whether it has a triple point with other states of matter given that we do not know what states of matter border this form of hydrogen. This makes (A) incorrect. The density should be greater given we are told the atoms are extremely close together and that it is under very high pressures - thus its density should be very high. We are left only with (C) and indeed it makes sense that if its electron clouds overlap significantly, that the electrons can become delocalized and thus conduct electricity.
According to Signal Detection Theory, the probability that which of the following will occur increases when one increases the probability of a hit? A. Miss B. Correct Rejection C. False Alarm D. False Rejection
C. When detecting a signal, there are two possible scenarios. The first is that the signal is not actually present, and the second is that the signal is present. If the signal is stronger than the criterion of selection, we will record it as being present (resulting in either a hit or a false alarm). Otherwise, it will be recorded as not being present (resulting in a correct rejection or a miss). Decreasing the criterion of selection leads to an increased chance of a hit (saying that a signal is present when it is actually so). However, decreasing the criterion also increases the chance of a false alarm (saying that a signal exists when in reality it does not exist) occurring. Increasing the chance of a hit (by lowering the criterion of selection) decreases the chance of a miss by making it less likely that a signal will be present but will simply not be strong enough to be detected. Thus, the answer is (C).
A weak acid (HA) is titrated in a beaker with a strong base (B⁻) such that equivalent molar amounts of each is added. Which of the following substances will not be found in the beaker at the end of titration? (I) HA (II) A⁻ (III) B⁻ (IV) HB A. All of the above substances will be present in solution. B. I and III only C. III only D. I, II, and III only
C. With a titration of a weak acid with a strong base, first the base deprotonates all of the acid, thus we have HB and A⁻. Because HB is a weak acid, A⁻ is a relatively strong base, so it will deprotonate some of the water in solution resulting in the formation of some HA. The only substance that will not be in solution is B⁻, thus (C) is correct.
Which of the following best describes the movement of an electron after it is ejected from a cathode? A. it is stationary until collisions propel it toward the anode B. it moves with constant speed toward the anode C. it accelerates toward the anode D. it exits through a side of the vacuum photodiode
C. a charged particle always accelerates in an electric field, the velocity of the electron increases as it approaches the vacuum F = Kqq/r^2, force increases as charges get closer, F/m = a. increasing force increases acceleration
A glass fiber carries a light digital signal long distances with a minimum loss of amplitude. What optical property of glass allows this phenomenon? A. Dispersion B. Refraction C. Reflection D. Diffraction
C. light can be carried along a distance within transparent material by means of total internal reflection
in acidosis body responds by breathing more and so
CO2/HCO3 conc can decrease so blood PH increases
CAM (protein)
Cadherin: Ca2+ Integrin: protein signal Selectin: carbs, immune system
Work=
Change in K energy K energy = 0.5m(vf^2 -vi^2)
Aldol reactions
Condensation: Aldehyde/ketone (nuc/electro). Form aldehyde & alcohol. Nuc (enolate), protonate -Retro aldol: Form aldehyde/ketone. Catalyzed by heat & base. Deprotonate OH group. LG (enolate)
An organic molecule has been isolated from the nucleus of a human cell. Nuclear magnetic resonance studies reveal the core structure of the molecule to be a six-membered ring containing carbon and nitrogen. The ring also expresses an amine group and a keto group, and is attached to a five carbon sugar moiety. No phosphate groups are noted. What is the most likely identity of the molecule? A. Cytosine B. Guanosine C. Guanine D. Cytidine
Cytidine First, realize that this question is asking you to identify a likely molecular component of the nucleus, DNA. DNA is largely made up of the nucleobases Adenine, Guanine, Cytosine, and Thymine. When these bases are attached to a ribose moiety, the five carbon sugar described in the question, they are called "nucleosides", and are named as Adenosine, Guanosine, Cytidine, and Thymidine. There are two main categories of nucleobases. Pyrimidines are made of a six membered heterocyclic ring of carbon and nitrogen with various substitutions on it's four carbon atoms. Purines are made of a pyrimidine plus an imidazole ring made of two nitrogens and a carbon atom. Adenosine and Guanosine are nucleosides made from purines while Thymidine and Cytidine are made from pyrimidines. The most likely identity of the molecule in question is Cytidine.
Researchers feed mice unsaturated fats as part of an experiment on weight gain and appetite. Which of the following represents a fat with the most double bonds? A) 18:1∆-9 B) 18:2∆-9,12 C) 28:1∆-17 D) 28:3∆-9,17,23
D) 28:3∆-9,17,23 The first number indicates the number of carbons, and the second number indicates the number of double bonds. The numbers after the "∆-" indicate the positions of the double bonds. So, in the correct answer, there are 28 carbons with 3 double bonds starting at carbons 9, 17, and 23 (choice D is correct). Answer choices A and C have one double bond while answer choice B has two double bonds (choices A, B, and C are incorrect).
Which primer is most suitable for PCR? A) 5'-ATTAGTA-3' B) 5'-ATTAGTAATTAGTA-3' C) 5'-GCGATATC-3' D) 5'-GCGATATGCGATATC-3'
D) 5'-GCGATATGCGATATC-3' Primer stability is governed by length of the primer, GC content, and the presence of 5' or 3' G's and C's. Answers A and B are eliminated due to their high AT content and low GC content. Answer C is eliminated when compared to Answer D as D is longer.
Which of the following was the neutral stimulus in the Pavlov classical conditioning experiments? A) Food B) Salivation C) Water D) Bells
D) Bells Food was the unconditioned stimulus that produced the unconditioned response of salivation (choices A and B are incorrect). Water was not used in the Pavlov experiments (choice C is incorrect). Bells were the neutral stimulus paired with food in order to transition the bells into the conditioned stimulus over time (choice D is correct).
Which of the following is NOT a function of the skin? A) Osmoregulation B) Physical barrier C) Thermoregulation D) Calcium release
D) Calcium release Osmoregulation, serving as a physical barrier, and thermoregulation are primary functions of the skin.
A student laughs at a funny joke after watching several other students start laughing. This action is best described by: A) Social facilitation B) Social loafing C) Obedience D) Conformity
D) Conformity Conformity occurs when an individual acts like his or her peers in an attempt to fit in (choice D is correct). Social facilitation describes the tendency of an individual to perform a simple task better when other people are around (choice A is incorrect). Social loafing describes the tendency of individuals to not work as hard when they are in a group (choice B is incorrect). Obedience occurs when an individual changes his or her behavior in response to an authority figure with the power to enforce the request (choice C is incorrect).
Which of the following is NOT true about DNA and RNA? A) Only DNA contains thymidine compared to RNA B) DNA is more commonly found as a double stranded structure compared to RNA C) DNA and RNA both have a 1' nitrogenous base D) DNA contains a 2' OH group
D) DNA contains a 2' OH group DNA contains an H, not an OH, at the 2' C position. For that reason, it is called deoxyribonucleic acid (DNA) instead of ribonucleic acid (RNA) (choice D is correct). RNA does not contain thymidine base pairs and instead uses uracil (choice A is incorrect). RNA is generally found as a single stranded structure whereas DNA is usually seen as a double stranded structure (choice B is incorrect). Both DNA and RNA do contain a 1' nitrogenous base (choice C is incorrect).
Which of the following structures is derived from the endoderm during human development? A) Skin B) Cardiac muscle cells C) Red blood cells D) Digestive cells
D) Digestive cells Digestive cells, and most epithelial cells, are derived from the endoderm. Skin is derived from the ectoderm (choice A is incorrect). Cardiac muscle cells and red blood cells are derived from the mesoderm (choices B and C are incorrect).
A student fails a test, and the teacher attributes this to the student's intelligence. However, the student broke her foot and had surgery during the week leading up to the exam. The teacher's mistake is an example of: A) Looking-glass self B) Stereotype threat C) Self-fulfilling prophecy D) Fundamental attribution error
D) Fundamental attribution error Fundamental attribution error describes the tendency to assume dispositional attributions (i.e. the student's intelligence) instead of situational attributions (i.e. the student's foot injury) (choice D is correct). The looking-glass self concept states that individuals behave based on how they think others perceive them (choice A is incorrect). Stereotype threat describes the phenomenon in which stereotyped individuals conform to stereotypes about themselves (choice B is incorrect). The self-fulfilling prophecy concepts occurs when an individual expects a certain outcome, and their behavior subconsciously leads to that outcome (choice C is incorrect).
Which of the following is NOT a disaccharide? A) Sucrose B) Lactose C) Maltose D) Galactose
D) Galactose Galactose is a monosaccharide (choice D is correct). Sucrose, lactose, and maltose are disaccharides.
Which of the following biological processes is the LEAST likely to contribute to genetic diversity among identical species in a population? A) Mutation B) Crossing-over C) Gene amplification D) Gene transcription
D) Gene transcription Gene transcription is a basal process carried out by cells thousands of times every day, and therefore it is necessary that this process is extremely accurate to ensure the survival of our cells. In addition, gene transcription produces RNA and does not change the DNA. As a result, the act of transcribing genes is not likely to lead to genetic diversity, especially when compared to the other answer choices (choice D is correct). Mutation, crossing-over during meiosis, and gene amplification are all changes that occur in the DNA and will therefore contribute genotypic changes to species in a population.
A red flower is mated with a white flower, resulting in pink progeny. This is an example of: A) Co-dominance B) Heterodominance C) Complete dominance D) Incomplete dominance
D) Incomplete dominance Incomplete dominance describes the "mixing" of two phenotypes, which is what occurs when a red and white flower are mated to form a pink (intermediate phenotype). Co-dominance describes both phenotypes being shown, which would mean daughter progeny have both red and white splotches (choice A is incorrect). Complete dominance describes normal dominance, which would be red flowers in this case if the red flowers are dominant (choice C is incorrect). Heterodominance is a made-up term (choice B is incorrect).
A point mutation in the DNA sequence for an important protein causes a valine to cysteine mutation at residue 86. This is an example of a: A) Nonsense mutation B) Frameshift mutation C) Active site mutation D) Missense mutation
D) Missense mutation A missense mutation occurs when a point mutation causes a single amino acid substitution. A nonsense mutation occurs when a point mutation leads to a stop codon and premature termination of the protein product (choice A is incorrect). A frameshift mutation is due to an insertion or deletion of bases (choice B is incorrect). The mutation might be an active site mutation, but there is not enough information given by the question stem to determine that the mutation is definitely in the active site (choice C is incorrect).
Researchers are testing the kinetics of a novel enzyme inhibitor. After assessing Michaelis-Menten kinetics, they conclude that the inhibitor binds to both the enzyme alone and the enzyme-substrate complex, though it binds to the enzyme alone with a slightly higher affinity. This is an example of: A) Competitive inhibition B) Noncompetitive inhibition C) Uncompetitive inhibition D) Mixed inhibition
D) Mixed inhibition Mixed inhibition occurs when an inhibitor binds both the enzyme alone and the enzyme-substrate complex. In this case, the inhibitor may bind the enzyme alone 60% of the time while binding the enzyme-substrate complex 40% of the time. Competitive inhibition occurs when an inhibitor binds the active site of an enzyme (choice A is incorrect). Noncompetitive inhibition is a subclass of mixed inhibition that describes an inhibitor binding an allosteric site, and this type of inhibitor binds the enzyme alone and enzyme-substrate complex with equal affinity (choice B is incorrect). Uncompetitive inhibition occurs when an inhibitor binds the enzyme-substrate complex alone (choice C is incorrect).
An individual attends a cultural event in which individuals from many different cultures attend, eat various foods, and talk about their experiences. This is an example of: A) Culture lag B) Culture shock C) Assimilation D) Multiculturalism
D) Multiculturalism Multiculturalism occurs when individuals of different cultural backgrounds co-exist (choice D is correct). Culture lag describes the tendency of culture to lag behind technological innovations, thereby leading to tensions in society (choice A is incorrect). Culture shock describes the feelings of disorientation felt by an individual who experiences a new culture for the first time (choice B is incorrect). Assimilation occurs when an individual begins to lose characteristics of his or her previous culture and gain characteristics of the culture that he or she is in (choice C is incorrect).
A DNA-binding protein is found to contain several arginine residues in the DNA-binding pocket. Which region of DNA does this protein most likely interact with? A) Nitrogenous base B) 2' H C) 3' OH D) Phosphate backbone
D) Phosphate backbone The phosphate backbone is negatively charged, so it can interact with the positively charged arginine residues. The nitrogenous base (A,T,C,G) is less likely to form a strong interaction with the positively charged residues (choice A is incorrect). The 2' H and 3' OH are small and will interact very weakly with the arginine residues (choices B and C are incorrect).
The G34R histone H3.3 variant is best described at having which type of R group at position 34? A) Nonpolar, aliphatic B) Polar, uncharged C) Aromatic D) Positively charged
D) Positively charged The G34R histone H3.3 variant would have a glycine to arginine substitution at positive 34, according to conventional nomenclature. Arginine is positively charged (choice D is correct; choices A, B, and C are incorrect).
Which of the following is NOT a primary function of the smooth endoplasmic reticulum? A) Steroid synthesis B) Lipid synthesis C) Metabolic byproduct detoxification D) Protein degradation
D) Protein degradation Protein degradation is generally carried out by the proteasome (choice D is correct). Steroid synthesis, lipid synthesis, and metabolic byproduct detoxification are all primary functions of the smooth endoplasmic reticulum.
Alternative splicing produces which of the following: A) DNA isoforms B) Identical mRNAs C) Larger-than-normal proteins D) Protein isoforms
D) Protein isoforms Alternative splicing produces protein isoforms, which are proteins with different exons and slightly different sequences (choice D is correct). DNA isoforms do not exist as DNA is unchanged by alternative splicing (choice A is incorrect). Identical mRNAs are not produced since exons are spliced together in different ways by alternative splicing (choice B is incorrect). While the proteins may be larger-than-normal, this is not always the case (choice C is incorrect).
One researcher hypothesizes that G-CSFRs activate the MAP kinase pathway. Which of the following protein residues is most likely to be altered by this pathway? A) Tryptophan B) Arginine C) Glutamate D) Serine
D) Serine Serines contain a hydroxyl group (-OH) and are therefore able to be phosphorylated by kinases (choice D is correct). Tyrosine and threonine can also be phosphorylated. Tryptophan, arginine, and glutamate do not contain hydroxyl groups (choices A, B, and C, are incorrect).
RNA often forms complex secondary structures. Which of the following is NOT a method researchers could use to study the structure of RNA molecules? A) Compensatory mutations followed by activity assays B) X-ray crystallography C) Cryo-EM D) Size-exclusion chromatography
D) Size-exclusion chromatography Size-exclusion chromatography is a purification technique, but it would not provide helpful information about the structure of RNA molecules (choice D is correct). Compensatory mutations followed by activity assays would allow researchers to identify which bases in the RNA molecule form base pair interactions with one another, thereby allowing researchers to determine structural contact points (choice A is incorrect). X-ray crystallography and cryo-EM are commonly used techniques to determine the 3D structure of biological molecules (choices B and C are incorrect).
A novel kinase inhibitor binds to the enzyme-substrate complex alone. Which of the following best describes the type of inhibition carried out by the inhibitor? A) Competitive B) Mixed C) Noncompetitive D) Uncompetitive
D) Uncompetitive Uncompetitive inhibition occurs when the inhibitor binds to the enzyme-substrate complex alone (choice D is correct). Competitive inhibition occurs when the inhibitor binds to the enzyme's active site (choice A is incorrect). Mixed inhibition occurs when the inhibitor binds to both the enzyme alone and the enzyme-substrate complex (choice B is incorrect). Noncompetitive inhibition is a form of mixed inhibition in which the inhibitor binds equally to the enzyme alone and the enzyme-substrate complex (choice C is incorrect).
In which of the following biological structures is blood pressure the smallest? A) Artery B) Arteriole C) Capillary D) Venule
D) Venule Blood pressure is the highest in arteries as these blood vessels are used to transport blood through the entire body (choice A is incorrect). Arterioles have the second highest blood pressure of the listed answer choices (choice B is incorrect), followed by capillaries (choice C is incorrect), and then venules (choice D is correct).
A 2-foot-by-2-foot square plate capacitor is used to store electrical energy for a science project. Plates are separated by a distance of 0.25 inches. Which of the following does not hold true regarding this set up? A. Changing distance between the plates to 0.5 inches will decrease capacitance. B. Capacitance is proportional to the total charge separated by the plates. C. Replacing the plates with circular plates of radius 1 foot will decrease the capacitance. D. All of the above hold true.
D. (D) is the correct answer - all of the answer choices are true facts. All of them follow from the equation Capacitance = Ae/d, where A is area, e is the dielectric constant, and d is distance between the plates. Option (C) requires a bit of thought - the area would be decreasing to pi = 3.14 ft² (from a previous area of 4 ft², thus capacitance would decrease.
Meiosis II occurs for the production of sex cells (sperm and eggs). For the egg, meiosis II actually occurs after the egg is fertilized by a sperm. Which of the following would not be expected to be found within the egg cell membrane after this meiosis process takes place? A. Sperm DNA B. Two polar bodies C. Enzymes from the sperm D. The zona pellucida
D. (D) is the correct answer - the zona pellucida lies outside of the egg cell membrane. It is a glycoprotein layer the sperm must pierce in order to get into the egg cell. All of the components would be expected to be found. There would clearly be sperm DNA because meiosis II occurs post-fertilization. There would also be two polar bodies - one is formed after meiosis I and one after meiosis II. Similarly, sperm enzymes might be expected to be found because those enzymes were used for the sperm to penetrate and get into the egg cell.
How many signals for ¹³C-NMR would we expect for bromobenzene? A. 1 signal B. 2 signals C. 3 signals D. 4 signals
D. A ¹³C-NMR on bromobenzene would show 4 distinct signals (from 4 groups of distinct, equivalent carbon groups). Carbon 1 (with the bromide) produces its own signal. Carbon 2 and 6 are equivalent and create their own signal. Carbon 3 and 5 are also equivalent and create their own signal. The final signal is created by carbon 4.
The liver enzyme AST is an important marker of liver damage. It catalyzes the formation of oxaloacetate and glutamate from aspartate and α-ketoglutarate. Which of the following enzyme classes best describes the function of AST? A. Oxidoreductase B. Hydrolase C. Lyase D. Transferase
D. AST, or aspartate aminotransferase, is a transferase because it transfers an amino group from aspartate to α-ketoglutarate, making glutamic acid and oxaloacetate.
If an individual were treated with a drug that inhibited the production of actin, which would NOT be directly affected? A. Muscle contraction B. Lymphocyte motility C. Villi and microvilli formation D. Desmosome cell junction
D. Actin is an important component of the cytoskeleton which contributes to eukaryotic cell shape (villi and microvilli), motility (including lymphocytes), and muscle contraction (actin-myosin mechanism). Desmosomes are primarily formed and strengthened by keratin rather than actin, making (D) correct.
Ca²⁺ ions can be readily sequestered from solution by precipitation with ions such as carbonate. Sodium, however, is difficult to sequester because sodium: A. is a smaller ion. B. has a lower ionic charge. C. is more reactive than calcium. D. has few insoluble salts.
D. Although (A) through (C) are true, they do not adequately explain why sodium is difficult to sequester in solution. Magnesium is smaller than calcium but can be sequestered in similar ways, making (A) incorrect. Silver has a lower ionic charge but has several insoluble salts making (B) incorrect. (C) is incorrect because reactivity is not directly related to solubility. (D) is the correct answer as very few insoluble sodium salts exist, meaning it is very difficult to sequester from a solution by reacting it with another ion.
A substance is brought to its triple point and the pressure is raised while keeping the temperature constant. The substance will therefore end up in which state? A. Gas B. Solid C. Liquid D. The answer cannot be determined with the given information.
D. An increase in the pressure would result in a favoring of either the liquid or the solid state, depending on which is denser. Since we do not know the slope of the solid/liquid interface, we can't conclusively determine the state of matter that the substance would be in.
Which of the following has the largest atomic radius? A. F B. F⁻ C. Cl D. Cl⁻
D. Atomic radius increases from right to left and top to bottom on the periodic table. Anions are larger than neutral species due to electron repulsion. Since Cl is lower than F on the periodic table, it has the larger radius. The ionic form of Cl would be larger than neutral Cl. Thus, the correct answer is (D).
Beta cells are cells in the pancreas which release insulin after eating a meal. Which of the following could be seen intracellularly in such cells? A. Bile salt transporters localized to the nucleus B. Peptidoglycan in the cellular membrane C. High concentrations of actin filaments D. A relatively large amount of rough ER
D. Beta cells need to produce very large amounts of insulin, which is a peptide hormone. Therefore, we would expect to find very high amounts of ribosomes and rough endoplasmic reticulum (to produce such large amounts of protein) therefore (D) is the correct answer. (A) is incorrect because bile salts have nothing to do with beta cells. (B) is incorrect - peptidoglycan is found in the cell walls of bacteria. (C) is also incorrect because there is no reason to assume there would be more actin filaments in these cells.
Which of the following systems has the lowest entropy? A. Water at 80°C B. Water at 100°C C. Steam at 100°C D. Pewter at 80°C
D. Entropy is a measure of disorder, or randomness, of a system. The more disordered a system, the greater its entropy. Gases have the highest entropy then liquids, and solids are the most ordered of the three phases. Pewter at 80°C is a solid, so it has the lowest entropy.
Which of the following is not an assumption made for a population in Hardy-Weinberg equilibrium? A. The population has an infinite size. B. The population does not experience any mutation. C. There is no migration to or from the gene pool. D. The population undergoes natural selection through selective breeding based on fitness.
D. Hardy-Weinberg equilibrium assumes the preservation of allele frequencies on a long-term basis. This would require that the genes are assorted randomly rather than selectively, and hence selective breeding would alter gene frequency over time. (A) through (C) are all assumptions of Hardy-Weinberg equilibrium as they all help maintain allele frequencies.
Which of the following molecules has the lowest vapor pressure? A. 2-propanone B. 2-butanone C. hexane D. 3-octanone
D. Having a low vapor pressure implies that the molecules have high intermolecular forces preventing them from evaporating. Two forces that we can look into are London dispersion forces and dipole-dipole. (a), (b), (d) have relatively similar dipole moments, and (c) has none, and we see that since (d) is larger than the other three, it has higher London dispersion forces than them. We see that (d) has the lowest vapor pressure because it has stronger London dispersion and dipole forces than the other molecules.
Suppose a ketone was a side chain for an amino acid. Upon heating, what might occur? A. Isomerization from D-form to L-form B. Formation of an epoxide ring and loss of oxygen C. Formation of a heterocyclic ring with two oxygens D. Decarboxylation and formation of an amine
D. If the side chain of an amino acid was changed to a ketone, the formation of a β-keto acid would occur. When β-keto acids are heated, they will spontaneously decarboxylate and lose CO. This would make the amino acid into an amine.
Similar to those found in carbohydrates, which type of protein linkage is most similar to a glycosidic linkage? A. Alpha helix B. Beta sheet C. Disulfide bond D. Peptide bond
D. In carbohydrates, a glycosidic linkage joins two 6-carbon monosaccharide units (like glucose and fructose, which form the disaccharide sucrose). Similarly, individual amino acids are linked via a peptide bond, which join the amino group of on amino acid to the carboxyl group of the other amino acid, forming a dipeptide. This process continues when forming much longer polypeptide chains.
Of the following atoms listed, which has a 2s orbital closest to its nucleus? A. Phosphorus B. Sulfur C. Chlorine D. Argon
D. In general, atomic size increases going down any column in the periodic table, since electrons fill the outer electron shells. Conversely, as we go across a row, the atomic radii decreases. And while more electrons are being added to atoms as we go from left to right, this is happening at smaller and smaller distances to the nucleus, since the increasing nuclear charge pulls the electron clouds inwards, making the atomic radii smaller.
A tennis ball is launched upward at an angle from starting Point A. Point B is at the top of its parabolic trajectory (the highest position of the ball above the ground), and Point C is when it hits the ground. At which point in its trajectory is the ball's velocity vector changing most rapidly with respect to time? A. Point A B. A point between Point A and Point C C. Point C D. The change in velocity is the same at any point in the trajectory
D. In this kinematics scenario, the change in velocity with respect to time is equal to the acceleration due to gravity (pointing downwards throughout) and it is the same at any point in the trajectory.
The nuclear reaction of ²⁶₁₃Al → ²⁶₁₂Mg is an example of which of the following types of nuclear decay? A. β- decay B. Alpha decay C. Gamma decay D. Electron capture
D. In this reaction, the number of nucleons remains the same (26) but the atomic number decreases from 13 to 12. This can either be due to the emission of a positron (β⁺) decay which would convert a proton into a neutron and decrease the atomic number, or it could be due to the absorption of an electron into the nucleus and its combination with a proton to form a neutron. Since the former option is not presented in the answer choices, the correct answer must be the latter. β⁻ decay would result in the emission of an electron from the nucleus which would increase the atomic number due to converting a neutron into a proton. Alpha decay would result in the loss of 2 neutrons and 2 protons, and gamma decay would not change the structure of the nucleus in terms of the number of protons and neutrons.
Three solutions are mixed, each with a high concentration of amino acids. Solution A has a high concentration of basic amino acids, Solution B has a high concentration of acidic amino acids, and Solution C is nearly all non-polar amino acids. Using isoelectric focusing as an electrophoresis method to distinguish these proteins, and given that the bottom of the gel is toward a lower pH, which of the following lists (from bottom to top) the positions of these proteins as a result of the separation? A. Basic proteins, non-polar proteins, acidic proteins B. Non-polar proteins, acidic proteins, basic proteins C. Acidic proteins, basic proteins, non-polar proteins D. Acidic proteins, non-polar proteins, basic proteins
D. Isoelectric focusing is the electrophoresis technique usually used for separating proteins by differences in their isoelectric point (pI), which is the point at which the net charge is equal to zero; therefore the protein will not migrate further in the gel. Isoelectric focusing utilizes the fact that the overall charge on the molecule of interest is a function of the pH of its surroundings. As a result, the proteins migrate into bands with each protein at a point in the pH gradient corresponding to its pI. Basic proteins will have a high pI, while acidic proteins will have a lower pI. Therefore, since the bottom of the gel is toward a lower pH, one would expect to see more acidic proteins there. And as pH increases going from the bottom of the gel to the top, non-polar and then basic proteins would be expected to be found.
Protein phosphotases usually do which of the following modifications? A. Phosphorylation B. Acetylation C. Methylation D. Dephosphorylation
D. Kinases phosphorylate (i.e. they add a phosphate group), while phosphotases remove a phosphate group, or dephosphorylate.
A scientist mutates the DNA that codes for a peptide sequence, producing a new peptide that has a higher isoelectric point. Which of the following mutations could explain this? A. Histidine to threonine B. Arginine to aspartic acid C. Tyrosine to phenylalanine D. Isoleucine to arginine
D. Most amino acids have isoelectric points around 6; amino acids with acidic chains have lower isoelectric points, while higher isoelectric points correspond to amino acids with basic side chains. So, to raise the pI of this peptide, we need to make a side chain more basic. The only answer choice that does this is choice D: isoleucine has a neutral side chain, while arginine has the most basic side chain of any amino acid used in proteins.
Which of the following would likely be inhibited after smoking a cigarette? A. Pupil dilation B. Vasoconstriction C. Glucose production D. Bladder contraction
D. Nicotine stimulates the sympathetic nervous system. Choices A, B, and C all describe functions that are stimulated by the sympathetic nervous system. Only Choice D is a function that would be inhibited, and is therefore correct.
A non-competitive inhibitor binds to an allosteric site and prevents substrate from binding to the active site. Non-competitive inhibition: A. is affected by concentrations of substrate. B. increases Vmax of a reaction. C. maintains constant Vmax of a reaction. D. cannot be overcome by increasing substrate concentration.
D. Non-competitive inhibition cannot be overcome by increasing substrate concentration because substrate is not competing with the inhibitor. Thus, (D) is the correct answer.
Both nucleophilic substitution and addition deal with the attack of a nucleophile onto an electrophile. The primary difference between the two, however, is that A. Nucleophilic addition involves a good leaving group while nucleophilic substitution does not. B. Nucleophilic addition can follow either SN1 or SN2 mechanisms while nucleophilic substitutions can only follow SN1 mechanisms. C. Nucleophilic substitution and addition are competing mechanisms for the same reaction. D. Nucleophilic addition involves the replacement of a π bond with two new σ bonds while nucleophilic substitution primarily occurs with the replacement of existing σ bonds.
D. Nucleophilic addition involves the attack of a nucleophile onto an electrophile, and, as the name implies, adds a group onto the electrophile. This typically happens in the context of C=O or other double- or triple-bonded groups where a π bond can be broken and substituted for new σ bonds; these compounds have space for the addition of new substitutent groups. Substitution usually occurs when there are already sigma bonds and one is simply replaced for another; there is no "space" for more sigma bonds. (A) reverses the situation; substitution has good leaving groups while addition need not have good leaving groups. (B) is a nonsense answer since SN mechanisms deal with substitution, and (C) is simply false.
Type I diabetes results from a lack of secretion of insulin, while Type II diabetes results from impaired sensitivity to insulin. Which of the following most accurately represents the relationships between type of diabetes and body habitus? A. Type I diabetics are likely to be overweight, while Type II diabetics are likely to be underweight. B. Type I diabetics are likely to be of normal weight, while Type II diabetics are likely to be underweight. C. Type I diabetics are likely to be overweight, while Type II diabetics are likely to be normal weight. D. Type I diabetics are likely to be underweight, while Type II diabetics are likely to be overweight.
D. One of the primary effects of insulin is the conversion of excess blood sugar to fat by adipocytes. When insulin resistance is present, this increases blood glucose. Adipocytes then lower blood glucose by storing excess glucose as fat. Type II diabetics tend to be overweight as a result of this insulin resistance. In addition, excess weight also contributes to insulin resistance, creating a cycle that contributes to weight gain in Type II diabetics. On the other hand, Type I diabetics lack insulin, due to autoimmune destruction of the beta cells of the pancreas. Thus, Type I diabetics are unable to use dietary glucose for any process that requires insulin for entry of glucose into cells. However, beta oxidation and gluconeogenesis are still intact. Thus, Type I diabetics (especially those who have not been diagnosed) are usually thin as the body is attempting to use fat and protein to create energy. Glucose produced by gluconeogenesis is not able to enter cells either, thus raising blood glucose levels even further.
Which of the following is TRUE regarding oxidative phosphorylation and electron carriers? A. Electron carriers are phosphorylated before being oxidized. B. Phosphorylation drives electron carriers to lower and lower energy levels. C. While oxygen is oxidized, ATP is produced by the phosphorylation of ADP. D. Through the process of electron transfer, an electrochemical gradient is created, and this drives the phosphorylation of ATP from ADP.
D. Oxidative phosphorylation is meant to break down NADH and FADH2, and forms an electrochemical gradient for hydrogen ions in the outer component of the mitochondria. As the hydrogen ions move down their concentration gradient through ATP synthase, ATP is generated from ADP.
A new manufacturer of heart and lung machines has found that the flow rate is insufficient for complete coronary bypass. Which of the following mechanical changes will cause a doubling in the flow rate from the machine? A. Doubling the diameter of the lumen B. Doubling the pressure exerted by the pump C. Doubling the length of the lumen D. Halving the viscosity of the blood with anticoagulant
D. Recall that Poiseulle's law governs the movement of fluids through a tube. Flow rate is directly proportional to the pressure drop across a space, inversely proportional to the length of the tube and the viscosity, and proportional to the fourth power of the radius. Therefore, halving the viscosity will result in a doubling of the volume flow rate. Choice A will result in a sixteen fold increase in volume flow rate, which may exceed the circulatory capacity, while choice B will more than double the pressure gradient since the ending pressure remains constant. Choice C results in a reduction of the volume flow rate.
Scientists use the lac operon to control eukaryotic protein expression. Provision of allolactose induces expression of the eukaryotic protein. What occurs in the absence of allolactose? A. The repressor binds RNA polymerase, preventing it from transcribing the eukaryotic genes. B. The repressor binds the structural gene, preventing RNA polymerase from transcribing the eukaryotic genes. C. The repressor binds the promoter, preventing RNA polymerase from transcribing the eukaryotic genes. D. The repressor binds the operator, preventing RNA polymerase from transcribing the eukaryotic genes.
D. Regulation of gene transcription enables prokaryotes and eukaryotes to control the synthesis of proteins. The regulator gene codes for the repressor molecule. The promoter gene is the site of binding for the RNA polymerase. The operator gene is the binding site for the repressor. When the repressor is bound, the RNA polymerase cannot transcribe past the operator and the structural gene cannot be transcribed. The structural gene encodes for the desired protein. When the inducer is present, the repressor and inducer bind each other. The operator is free and the RNA polymerase can transcribe the structural gene. When no inducer is present, the repressor binds the operator and prevents RNA polymerase from transcribing the eukaryotic gene.
Saponification of fatty acid leads to the formation of: A. an ester and a hydroxide. B. an epoxide and water. C. an aldehyde and a hydroxide. D. a carboxylic acid salt and water.
D. Saponification is the creation of soap, which involves mixing a fatty acid with lye, or sodium hydroxide. This means that an acid is mixing with a base, and neutralization occurs. As water is formed (by an -OH from NaOH and an -H from the carboxylic acid), there will be a negative charge on the newly formed carboxylate and free sodium with a positive charge. These will interact with each other to form a salt of that carboxylic acid, which is soap.
A lead sphere with a volume of 1 mL and a silicon sphere with a volume of 1 mL are dropped into water. What is the buoyant force on each sphere? Note: the density of lead is 11 g/mL and the density of silicon is 2.3 g/mL. A. The buoyant force is 0.11 N on the lead sphere and 0.023 N on the silicon sphere. B. The buoyant force is 0.00091 N on the lead sphere and 0.0043 N on the silicon sphere. C. The buoyant force on both spheres 11 N. D. The buoyant force on both spheres is 0.01 N.
D. Since each sphere has the same volume and the buoyant force is calculated as F = ρ_liquid•V_object•g, the buoyant force is the same for both spheres. This can be calculated as F = (0.001 kg/mL)(1 mL)(10 m/s²) = 0.01 N.
Red-green color blindness is X-linked in humans. If a male is red-green color blind, and both parents have normal color vision, which of the male's grandparents is most likely to be red-green color blind? A. Paternal grandmother B. Paternal grandfather C. Maternal grandmother D. Maternal grandfather
D. Since the gene is X-linked and the male is red- greed color blind, we know that the male received his X chromosome from his mother. Since the mother has normal vision, she must be a carrier, i.e. one of her X chromosomes has the gene for red-green color blindness. While she could have received this gene from either her father or mother, it is more likely from the father, because then there is a 100% chance that the daughter will carry the gene. The other case is where the maternal grandmother could either have or carry the gene, in which there would either be a 50% chance of passing the gene off to the daughter, or a low chance that the maternal grandmother would be red-green color blind. Therefore (D) is the correct answer.
Which alcohol is more acidic? A. tertiary alcohol B. secondary alcohol C. primary alcohol D. methanol
D. The acidity of alcohols is determined by the number of substituted groups on the carbon holding the hydroxyl group. The descending acidity of alcohols is: methyl > 1° > 2° > 3° This is due to the fact that the most stable conjugate base of the alcohol would be the conjugate of the most acidic alcohol. Since the negative charge (which causes instability) of the conjugate base is more disperse in the less substituted species, then methanol should be the most acidic since it has no substituted groups. Thus the correct answer is (D).
During the first step of glucose metabolism, an enzyme drives catalysis and binds glucose in its active site. A second site exists (away from the active site) which binds ATP (the eventual end-product of glucose metabolism). Which of the following is NOT correct in describing the mechanism behind the ATP-binding site on this enzyme? A. The ATP-binding site is an example of feedback inhibition. B. ATP acts as a non-competitive inhibitor of the enzyme. C. The enzyme is less active when ATP is present in high concentrations. D. The enzyme is more active when ATP is present in high concentrations.
D. The case described is an example of feedback inhibition. One site (the active site) exists to bind glucose, and the other exists to bind the end-product (ATP). This end-product is used to regulate the activity of enzymes in the metabolic pathway. The end-product (ATP) acts as a non-competitive inhibitor of the enzyme, since it does not want to compete with the actual glucose for the active site. Instead, when ATP is in high concentrations, this tells the system that more ATP does not need to be continually made, so its binding causes the enzyme to be less active, not more.
22.4 L of a gas at standard temperature and pressure (STP) weighs 28 grams. Which of the following is NOT correct? A. This gas could be CO. B. Even though the identity of this gas is not presented, the density of this gas at STP can be determined. C. This gas could be a mixture of CO and N₂. D. This gas could be 14 moles of H₂.
D. The condition of standard temperature and pressure (STP) allows us to perform calculations (such as solving for density) on gases. STP means the condition of 0 degrees Celsius and 1 atm of pressure. At STP, one mole of gas occupies the same volume (22.4 L) as any other gas at STP condition, and this has been proven experimentally. Given the molar weight, we know this gas could be CO (12 + 16 = 28), as well as a mixture of CO and N2₂, since each of these two respective gases have a molar weight of 28. Moreover, the density can certainly be calculated as simple mass over volume (28 / 22.4). The only statement that is not correct is D, since 14 moles of H₂ would not occupy 22.4 L. This is because by definition, 22.4 L at STP is the volume of one mole of gas.
Which of the following hormones is correctly matched with its correct organ of production? A. Insulin - thyroid B. Glucagon - parathyroid C. Human growth hormone - posterior pituitary D. Aldosterone - adrenal cortex
D. The correct answer is (D). Insulin and glucagon are peptide hormones involved in the regulation of blood glucose levels and are both produced by the Islets of Langerhans of the pancreas. Human growth hormone (aka hGH or somatotropin) is a peptide hormone involved in regulating the growth of cells in the body and is produced by the anterior pituitary. Aldosterone is a steroid hormone that targets the distal convoluted tubule of the kidneys to increase the re-absorption of chloride and sodium ions and secretion of potassium and hydrogen ions.
A capacitor is placed in a circuit containing a 13 V battery. The capacitor is composed of two circular metal sheets of radius R separated by a distance D. If R is doubled and D is halved, what is the effect on capacitance? A. Remains constant B. Increases 2 times C. Increases 4 times D. Increases 8 times
D. The equation for capacitance is C = Ae/d, where A is the area of the capacitor, e is a constant, and d is the distance between the sheets. If radius is doubled, then A (and thus C) increases four times, and if D is halved, then C is doubled, thus the capacitance increases 8 times and (D) is the correct answer.
A positively-charged particle is found to be moving in the same direction as a magnetic field toward the top of the page. The direction of the force that the particle experiences is: A. into the page. B. out of the page. C. towards the top of the page. D. The particle does not experience any force from the magnetic field.
D. The force a charged object experiences is equal to qvBsin(θ) where θ is the angle between the motion of the charge and the magnetic field. Since the two are moving in the same direction, the angle θ = 0. sin(0) = 0, so there is no force experienced.
Which of the following pairs of elements would have the highest reactivity? A. H and O B. C and O C. H and Cl D. Na and F
D. The general rule for reactivity is that it increases with larger differences electronegativity. The largest difference in electronegativities is between Na and F; therefore they will have the highest reactivity.
Older individuals typically experience deterioration of hair cells near the oval window. Thus, an older individual may experience difficulties with: A. sitting in silence due to ringing in their ears. B. hearing the sound of honking horns in traffic. C. distinguishing between a trumpet and a saxophone. D. hearing the sound produced by a high pitched whistle.
D. The hair cells near the oval window are responsible for high frequency pitches.
Pheochromocytoma is a tumor that develops in the adrenal medulla, resulting in excessive secretion of hormones. Which of the following is likely to be an effect of this kind of tumor? A. Decreased blood pressure B. Decreased metabolic rate C. Increased blood flow to intestines D. Increased heart rate
D. The hormones produced by the adrenal medulla can be viewed as a link between the nervous and endocrine systems. Catecholamines such as norepinephrine and epinephrine are secreted in response to sympathetic nervous system stimulation. Thus, excess catecholamines will result in the same responses seen in activation of the sympathetic nervous system including increased heart rate, increased blood pressure, increased metabolic rate, and decreased blood flow for digestive processes.
Researchers exclude an adult from the study because exercise does not have the same effect on him as it has on the other participants. Researchers note that he is also obese and constantly thirsty. These symptoms, taken together, indicate potential disorder in which of the following structures? A. Cerebellum B. Thalamus C. Pituitary gland D. Hypothalamus
D. The hypothalamus is a structure in the brain that regulates all of the functions mentioned in the question stem: arousal (sexual and otherwise), hunger, and thirst. The cerebellum and the thalamus are connected with fine motor control and sensory processing, respectively. The pituitary gland, while exercising some hormonal control over thirst and stress, does not mediate the hunger response.
When 1000 mL of 100% methanol is mixed with 1000 mL of water, less than 1950 mL of liquid results. This is most likely due to A. evaporation of some of both of the liquids prior to mixing B. evaporation of the solution after mixing, a process which increases the temperature of the solution C. cooling of the solution due to mixing, resulting in a denser solution with less volume D. adjustment of the hydrogen bonding of the liquids, resulting in a denser solution and hence, a smaller volume
D. The mixing of water with a number of organic liquids will change the density due to disruption, i.e. adjustment, of the hydrogen bonds. This changes the volume of the resulting solution.
Which of the following tropic hormones is likely secreted to great excess in congenital adrenal hyperplasia? A. TSH B. Growth Hormone C. FSH D. ACTH
D. The pituitary gland releases ACTH in order to stimulate cortisol production. However, cortisol production cannot occur in sufficient quantities due to a defect enzyme within the pathway. Thus, continuous ACTH stimulation results in enlarged, or hyperplastic, adrenal glands.
Which of the following is most likely true about the products of hydrolysis of PTH? A. They are taken up by the parathyroid gland and incorporated into new PTH molecules. B. They are rapidly removed from the nephron by active transport. C. They do not pass through the glomerulus. D. They are water soluble.
D. The products of hydrolysis are directly excreted in the urine. In order to be excreted in the urine, a substance must be water soluble. Water insoluble compounds are either stored in the body, converted to water-soluble products, or eliminated in the feces.
A newly discovered protein is studied in the laboratory and called dorminogen. Based on the nomenclature of proteins, it can be assumed that this protein: A. is a neurotransmitter. B. cleaves other proteins. C. is an intranuclear protein. D. is a precursor protein.
D. The protein name ends with the suffix '-ogen', which is usually reserved to signify zymogen (also known as precursor) proteins. For instance, trypsinogen and pepsinogen are precursors to the enzymes trypsin and pepsin. Thus (D) is the correct answer.
lf ATP synthesis was inhibited in the nervous system of an animal, which of the following best describes the major effect on neural function? A. The cell could not generate an action potential B. The cell could not propagate action potentials throughout its membrane C. The cell could not open voltage-gated channels D. The cell could not maintain its resting potential
D. The resting potential is the imbalance of electrical charge that exists between the interior of a cell and its exterior, and this is influenced mainly by sodium and potassium ions. At rest, there are relatively more sodium ions outside the cell and more potassium ions inside the cell. Because of the high permeability for potassium, the resulting membrane potential is usually close to the potassium reversal potential. In order for this imbalance to even occur, a concentration gradient is established, which is done by ion pumps/transporters that are powered by ATP. In the case of the resting membrane potential across an animal cell's membrane, potassium and sodium gradients are established by the sodium-potassium pump, which transports three sodium ions outside and two potassium ions inside, at the cost of 1 ATP molecule. If ATP synthesis was inhibited (for example, due to some inhibitor blocking ATP Synthase), this sodium-potassium pump would be compromised, as there is not enough ATP available to maintain a resting potential.
Assuming that all of the faucets are shut, where in a two-story house (with an open water storage tank located in the attic) will the water have the greatest pressure? A. At the shower faucet on the second flood B. At the kitchen and bathroom faucets on the first floor C. At the bathroom sink faucet on the second floor D. At the intake valve of the washing machine in the basement
D. This question requires knowledge that in a closed, static fluid system, the pressure only depends on the depth relative to the highest point. The deeper the point in the system, the larger the pressure will be. Since the washer is in the basement and is the lowest point, it will have the greatest pressure.
Radiation can affect cells in many different ways. Which of the following is the most likely consequence of a cell being irradiated with gamma radiation? A. DNA structure is altered B. Protein primary structure is altered C. Lipid is altered D. Water forms hydroxyl radical
D. Water is by far the most abundant molecule in all cells. It takes up in excess of 90% of the total mass of most living matter, and hence is the most likely target for any radiation. Much of the damaged caused by radiation is due to the formation of radicals which damage DNA, proteins, and membranes.
A particular enzyme-catalyzed biological reaction (Reaction 1) in humans takes the substrate A and converts it to B. The ΔG is -100 kJ/mol. A different enzyme is later found which also has A as a substrate (Reaction 2). The identity of the product from this different enzyme is not recorded. It is found that the ΔG for this new reaction is -120 kJ/mol. Which of the following holds true? A. Reaction 2 must run faster kinetically than Reaction 1. B. The second enzyme is more efficient at converting A to B due to the larger decrease in free energy. C. Reactant A can bind to 2 enzymes at a time. D. The product of Reaction 2 cannot be B.
D. We know that in a reaction A → B, the change in free energy will always stay the same. The only thing that may change is the activation energy (due to enzyme catalysis). Since reactions 1 and 2 have different ΔG values, we know that the second reaction CANNOT have B as a product. Therefore (D) is the correct answer. (A) is incorrect because ΔG does not inform you about kinetics - activation energy does. (B) is incorrect because we already know that reaction 2 does not form B. (C) is incorrect because there is nothing in the prompt to allow for this claim.
Aurora, called the Northern Lights in the northern hemisphere, result partly from nitrogen in the upper atmosphere. The nitrogen atoms are either ionized or excited, and emit light when returning to their ground state. Depending on whether the nitrogen is ionized or excited, the colors blue or red are emitted. Which of the following accurately describes the relationship between color and energy state? A. Ionized nitrogen returning to ground state produces red light while excited nitrogen returning to ground state emits blue light because there is a greater energy difference between ionization and ground than excitation and ground. B. Ionized nitrogen returning to ground state produces red light while excited nitrogen returning to ground state emits blue light because there is a greater energy difference between excitation and ground than ionization and ground. C. Ionized nitrogen returning to ground state produces blue light while excited nitrogen returning to ground state emits red light because there is a greater energy difference between excitation and ground than ionization and ground. D. Ionized nitrogen returning to ground state produces blue light while excited nitrogen returning to ground state emits red light because there is a greater energy difference between ionization and ground than excitation and ground.
D. We've got two separate issues here: the first is what color will be emitted and the second is why. It's perhaps easiest to first think about what's happening. Comparing two nitrogen atoms, one of them will be ionized (have completely lost its electron) while the other will simply be excited. Ionization energy is always greater than an excitation energy, because in excitation the electron remains with the atom whereas in ionization, enough energy is added to completely remove the electron. Thus in reverse; the gain of an electron or the dropping of the energy state, more energy is released for ionized → ground than excited → ground. This corresponds to the color difference since blue is a higher energy light than red, making (D) the correct answer.
Which of the following correctly describes the interactions present in the quaternary structure of a protein? A. Peptide bonds only B. Hydrogen bonds only C. Hydrogen bonds, ionic bonds, and phosphodiester bonds D. Hydrogen bonds, ionic bonds, and Van der Waals interactions
D. With regard to proteins, primary structure is the linear sequence of amino acids. Secondary structure is the general 3D format of segments of proteins (alpha helices, beta sheets) resulting from hydrogen-bonding between sections of the polypeptide backbone. Tertiary structure results from the interactions and bonds of side chains within a protein (this results in a single polypeptide chain - or backbone - with one or more secondary structures, and amino acid side chains may interact or bond in multiple ways). Lastly, quaternary structure is the arrangement of multiple, folded proteins or into a multi-subunit complex.
Which of the following correctly describes where glucagon stimulates the release of glucose? A. Adipose tissue B. Skeletal tissue C. Thyroid gland D. Liver
D. with insulin, glucagon is a hormone that is involved in controlling blood glucose levels: glucagon is released to stop blood sugar levels from dropping too low while insulin is released to stop blood sugar levels from rising too high. While the pancreas actually releases glucagon (during hypoglycemia), glucagon acts on the liver and causes it to convert stored glycogen into glucose, which is then released into the bloodstream.
What kind of object is emitted in the decay of 40K to 40Ar? A. a gamma ray B. and alpha particle C. an electron D. a positron
D. the 40K to 40Ar does not change in the atomic mass (40) of the nucleus, but does change in atomic number (19 to 18) showing a positron has been emitted. Same change could have occurred if an electron had been captured
At the equivalence point in a titration of a weak acid with NaOH, the pH is: A. < 4 B. > 4 and < 7 C. = 7 D. > 7
D. the pH at the equivalence point in any titration is the pH of the salt solution formed. The conjugate base of a weak acid is strong and the addition of NaOH increases the pH as well.
If the rate of formation of Cl- were 1.0 x 10^-2 at a pH of 1, what would it be at a pH of 2 if reaction is second order with respect to hydronium concentration? A. 1 x 10^-1 B. 1 x 10^-2 C. 2 x 10^-2 D. 1 x 10^-4
D. the rxn is second order with respect to H+. at a pH of 1, the hydrogen ion concentration is 1 x 10^-1. when pH is increased to 2, hydrogen ion concentration is 1 x 10^-2. The rate will therefore be [1 x 10^-2] x [1 x 10^-2] pH = -log[H3O+]
Taxonomy memorize
Dumb kings play chess on fine green sand Domain kingdom class order family genus species
At what point does crossing over between sister chromatids occur? A. During anaphase I of meiosis B. During prophase I of meiosis C. During anaphase II of meiosis D. During prophase II of meiosis
During prophase I of meiosis Crossing over is a form of genetic recombination in which homologous chromosomes pair up and exchange pieces of their genetic material. Crossing over occurs in prophase I of meiosis, and is often referred to as synapsis. However, crossing over occurs between homologous chromosomes, and not between the sister chromatids of an individual chromosome. Sister chromatids are identical pieces of DNA joined at the centromere to make up one chromosome.
Relationship between G, E, K
E (+), K > 1, G (-) E (-), K < 1, G (+)
The synthesis of which of the following would be LEAST affected by a disease which selectively destroys the smooth endoplasmic reticulum? A. Testosterone B. Phospholipids C. Insulin D. Cholesterol
Insulin The smooth ER is responsible for many functions, including the production of various lipid products and degradation of steroid hormones such as testosterone.Key steps in the synthesis of cholesterol occur within the smooth ER. Insulin is a peptide hormone, which is a product of the translation of mRNA, which occurs in the cytoplasm. The synthesis of Insulin would be least affected by a disease which destroys the smooth ER, but would be affected if the rough ER were affected.
Globalization
International trade, Cross-border investment, migration, & free flow of information
What is the danger of giving a patient with a bacterial infection an anti-inflammatory drug? A. It may decrease endogenous antibacterial activities B. It may increase the platelet count C. It may decrease the red blood cell count D. It may increase the blood pressure
It may decrease endogenous antibacterial activities The proliferation of inflammatory cells, including T cells, B cells, and other leukocytes, helps in fighting infections. Therefore, giving an infected patient anti-inflammatory drugs has the potential to reduce their ability to fight infection.
Which of the following is an alternative method of synthesizing benzoic acid? A. Benzyl alcohol
KMnO₄ B. Phenol + Tollens' reagent C. Benzaldehyde + NaBH₄ D. Cyclohexanemethanal + H₂CrO₄ + A. Since benzoic acid is a carboxylic acid, it can be synthesized by combining the corresponding alcohol (benzyl alcohol) or aldehyde (benzaldehyde) with a strong oxidizing agent.
Kinetic vs thermodynamic
Kinetic: fast, irreversible, ↓ temp, strong base Thermodynamic: slow, reversible, ↑ temp, weak base, stable, spont
Slope of Lineweaver Burk plot
Km/Vmax
How does one determine whether offspring will be fertile?
Looking at # of chromosomes
Doppler effect
Moving toward: Apparent > Emitted Moving away: Apparent < Emitted
Sarcomere
Myosin (thick, ATPase, primary motor protein) & Actin (thin via troponin/tropomyosin) M-line, I-band (thin), H-zone (thick), A-band (thick, constant size) Myofibril: site of attachment
Facts about NAD/NAD+/NADH/NADPH/NADP+
NAD+ : Product of ETC NADH: Used in breakdown of glucose for formation of ATP. Substrate. NAD: nucleotides are joined by phosphate groups NADPH: formed from PPP NADP+: stimulates PPP
NAD+/NADH vs. FAD/FADH2
NAD+/NADH: don't react with O2, unstable intermed, 2 e- transfers, not bound to enzymes FAD/FADH2: react with O2, stable intermed (semiquinone), 1 e- or 2 e- transfers, bound to enzymes
Can there be a doppler shift if there is no relative motion
NO!
Is the stress reposnse specific to the type of stressor?
NO!
Soluble vs insoluble
Soluble: Nitrates, acetate, Group I, ammonium, chlorate Insoluble: Halogen (precipitate), BaSO4 (in acidic cond)
How to determine systolic and diastolic pressure from a blood pressure reading
Systolic: first sound of blood heard when blood pressure in cuff falls below artery pressure Diastolic: pressure at which sound disappears
Henry's Law
The concentration of the dissolved gas depends on k
Tautomerization
The rearrangement of bonds within a compound, usually by moving a hydrogen and forming a double bond
What does it mean for a cancerous mutation to not be present in non-cancerous transcripts?
This means this is a spontaneous, not germ-line, mutation. It can't be passed on to offspring.
Pascal's Principle
When force is applied to a confined fluid, the change in pressure, is transmitted equally to all parts of the fluid
In the nuclear reaction ²³⁸₉₂U → ²³⁸₉₃Np
X what type of nuclear decay has occurred? A. Electron capture B. Positron emission C. Gamma emission D. Beta decay + D. In beta decay, a neutron converts to a proton and an electron, and the electron is emitted from the nucleus as a beta particle. The nucleus, in turn, increases the number of protons from 92 to 93 but decreases its number of neutrons accordingly, thus retaining the same number of protons + neutrons.
Protein analysis
X-ray (structure), Edman/hydrolysis (amino acid), Color (activity), UV (protein concent)
during ovulation, is the egg that's released a secondary oocyte or ovum?
a secondary oocyte bc it hasn't undergone meiosis 2!!
how do you differentiate between and aldose and a ketose in their cyclic form?
aldose: has ONE CH2OH ketose: has TWO CH2OH
as you move left on an T-NMR spectrum, what happens to deshielding, chemical shift and frequency?
all increase
the force that allows objects to stay afloat
buoyant force
conflict theorists
culture generates enormous inequality -class based, power, structure, social stratification
step down transformers decrease the voltage while increasing the
current (power remains constant)
when breaking molecules apart or overcoming other intermolecular forces is this action endothermic or exothermic
endothermic because you need energy to do that
What activates trypsinogen? chymotrypsinogen?
enteropeptidase, trypsin
Brain technique
fMRI: measures brain activity in response to blood flow MRI: measures structures of brain/tissue PET: localizing brain areas
Incentive theory involves what factors that influence motivation
factors outside individuals. Note: community prevention efforts and aspects of culture are also covered under incentive theory
T or F? the components of the plasma membrane are set in place
false: the membrane is a FLUID MOSAIC model i.e. the components are fluid and can move around
What's a zygote?
fertilized egg (sperm + egg) - contains genes from both parents
Groupthink
group members seek agreement despite individual doubts
Psychoanalytic theory
id: innate/nature superego: perfectionist ego: conscious/defense mechanism
what happens if we have too much testosterone?
increased prostate cancer risk, increased MPB
how does pressure affect buoyant force? what happens to the force as you dive?
it doesn't affect it! the buoyant force remains the same as you dive
Where does most absorption occur?
jejunum
Fe= (magnitude of electrostatic force
kq1q2/r^2 r = distance between 2 charges (q) k is coulomb's constant
mitral valve is between
left atrium and left ventricle
More intermolecular and hydrogen bonding means ___ solubility?
less
low LH and Low FSH what is happening
menstration
reactivity trend, why is it diff for metals and non-metals?
metals: increases down a column, to the left non-metals: increases up a column, to the right * for metals, they get reactive by losing an elec, while non-metals get reactive by gaining an elec
what component has the most prominent role in the cleavage and contractility of the cytoplasm (helps things move)
microfilaments
electrolytic solutions are good with
more ions
Deshielded proton = more/less freq = more/less chemical shift = upfield or downfield?
more, more, DOWNFIELD
Where does mitochondrial DNA come from?
mother
when an atom absorbs energy its electrons ____
move from ground to a higher energy level
Acetocholine is a
neurotransmitter that when in synaptic cleft will increase muscle twitch frequency
Does the volume submerged depend on the gravitational constant?
no because the relative density will be the same
changing the 3rd nucleotide in a base pattern will have
no effect usually because there is a wobble on a third nucleotide especially if its changing from pyrimidine to pyrimidine or purine to purine
Product of sucrose reacting with silver?
no reaction because sucrose is not a reducing sugar
ideal ammeters have
no resistance
during uniform circular motion
no work is done
would giving estrogen to men decrease osteoporosis the way it does for women?
no!
when G is bigger than 0
non spontaneous
What does flaccid mean?
non-erect penis
Paramagnetic
not retaining any permanent magnetism but weakly attracted by the poles of a magnet (atom with one or more unpaired electrons) its pulled into an external magnetic field
A therapist wishing to implement a treatment based on the stress generation hypothesis will likely pay a great deal of attention
preventing the recurrence of depressive episodes
increase in temp favors what side of rxn
products which increases the concentration of H+ and OH- ions which increases the Kw
how many ATP are produced in prokaryotes vs eukaryotes?
prokaryotes: 32 eukaryotes: 30 *however, note that in glycolysis, they both have the same net ATP*
pepsin
protein digesting enzyme secreted by the gastric glands of the stomach.
k for protein unfolding
protein unfolding is a unimolecular mechanism, so k has units s^-1
What kinds of macromolecules are digested in the STOMACH?
proteins
When the environmental temperature is 33C, vasodilation of cutaneous blood vessels helps to regulate the body temperature of a human by: A. slowing blood flow through the skin B. maintaining an even distribution of heat throughout the body C. radiating excess body heat into the environment D.preventing needed body heat from being lost to the environment
radiating excess body heat into the environment When vasodilation occurs, the blood vessels relax, allowing more blood to enter the area. The presence of increased blood within dilated vasculature in cutaneous tissue allows heat to escape from the surface of the body into the environment. Vasodilation increases blood flow and facilitates heat loss.
Periodic Table Trends
radius: increases down left acidity: increases down right IE, Electron affinity, EN: increases top right (for EA, it increases negatively)
Tubular transport maximum
rate of transport that exceeds the capacity of the kidney to reabsorb the substance
proximal stimulus
registered by sensory receptors
renal hilum
renal artery + renal vein + ureter
renal blood supply
renal artery-> afferent arteriole-> glomerulus-> efferent arteriole-> peritubular capillaries/vasa recta-> venules-> renal vein
pathway of urine collection in nephron
renal calyx ---> renal pelvis ----> ureter ---> bladder ---> urethra
outer part of the nephron = inner part =
renal cortex, renal medulla
Ultrasound
required speed of sound & frequencies of sound waves emitted & observed.
Postmenopausal women receiving estrogen and progesterone therapy will have what side effect?
resumption of periodic menstruation
monocular depth cues
retinal height, occlusion, & texture gradient
sign-inverting synapse
reverses the polarity of the response
competitive inhibitors bind how
reversibly to active site
tertiary structure is made by
salt bridges and hydrophobic structures along with disulfide bonds and hydrogen bonding
How is glucose reabsorbed?
secondary active transport 1- 1- lumen ===> epithelial: symport with Na (2ndry active) 2- epithelial ===> interstitial: diffusion using GLUT channels 3- interstitial ===> blood: diffusion
reporting bias
selective revealing/suppression of info by subjects
Extrachromosomal genes are
self-replicating don't have to be circular but can be
accessory male sex glands
seminal glands, prostate, and bulbo-urethral glands
Isoelectric focusing
separates proteins based on differences in pI
Affinity chromatography
separates proteins based on interaction with specific ligands
Gonads
sex gland responsible for menopause, puberty etc.. in males: testes in females: ovaries
Bonds
shorter = smaller atomic radius / mass
basolateral surface
side facing interstitial space/capillary
apical side of bowman's capsule
side facing lumen
will water or mercury have a greater maximum buoyant force? (density of mercury: 13500 Kg/m^3)
since the Force buoyant = volume of object submerged • g • density of liquid - the only variable part is the density, and since mercury is denser = mercury will have a greater buoyant force
central vein
sits in the middle of hepatic lobule, carries venous blood back to heart via hepatic veins
what is Ksp?
solubility product constant
Routs Law states that Ideal solution behavior is observed when
solute solute, solvent solvent and solute solvent interactions are all very similar. all about how things are similar
which has a bigger EN, sp2 or sp3?
sp2 bc it has a greater s percentage .˙. closer to nucleus
Promoters
specific region of gene where RNA polymerase binds & begins transcription
What property of a sound remains constant after reflecting off a surface
speed!
geminal coupling meaning
spin-spin splitting that occurs with 2 protons that are on the SAME carbon
if E˚ cell is positive, is the rxn spontaneous or not?
spontaneous! if the FREE ENERGY is +, then its not spontaneous
Kw= 1* 10^-13 (10 times more than neutral)
square root it it comes out to 1*10^-6.5 so negative log it and its 6.5 for both ph and poh
What step must be completed before isoelectric focusing can be performed
stable pH gradient must be established
a log graph translates to a __________ on log scales
straight line wih non zero slope if ther is variation with time
An enzyme is more effectively inhibited by an uncompetitive inhibitor when
substrate and enzyme concentration increased (because it binds ES complex)
Ksp < IP
supersaturated
proper hepatic artery
supplies liver with oxygen-rich blood
action potential causes
t tubule depolarzation
protein folding is most likely to be disrupted at the level of _____ structure of protein
tertiary
what protein structure is most important for enzyme function
tertiary structure
what are the primary male sex organs?
testes (2) + penis
what is the major male sex hormone?
testosterone
negativity bias
the tendency to focus or remember the negative aspects of experiences
Enzymes do not effect
thermo of reaction
how are hormones taken up by the target cell??
they float in the blood and the target cell/organ takes them via the specific RECEPTOR it has for the hormone
whats an amine and an amide
they're groups on organic molecules that have an N in them the amine is surrounded by r groups and the amide has a c double bonded to O right next to it
how does blood flow into the 2 corpora cavernosa?
through the dorsal and cavernosal arteries
thyroxine is in the
thyroid (it comes from it) it helps regulate metabolism
Goiters occur because of a deficiency in
thyroxine
epithelial cells in the convoluted tubule are connected by
tight junctions gap junctions are too leaky
korte's law
time and distance are related
steps of spermatogenesis
to make sperm Begins before puberty 1. spermatogonium cells divide by MITOSIS. 2. One cell differentiates into a primary spermatocyte, and the other remains a spermatogonium that will go through MEIOSIS at some time in the future. 3. Primary spermatocytes begin meiosis and produce secondary spermatocytes (23 pairs of chromosomes each) 4.These differentiate into spermatids (23 SINGLE chromosomes each) 5. Spermatids differentiate into sperm
what are the 3 parts of the esophagus?
top: all skeletal middle: mix of both bottom: all smooth
ATP dependent phosphorylation of a target protein is carried out by a
transferase
what kind of epithelium lines the bladder?
transitional epithelium
T or F: the liver receives nutrients from the intestine to store
true
A floating object displaces its
volume
What does the colon absorb?
water and electrolytes (inorganic ions)
purpose of large intestine
water, ion, vitamin absorption
Muscle cell
↓ O2 debt/fatigue through creatine phosphate & myoglobin
Isochoric
delta V = 0 so work equals zero
Archimedes principle
density = weight (air) / weight (air) - weight (water)
phase change
density and entropy change
what happens to the energy difference between alpha and beta spins as the magnetic field increases?
difference in energy increases
how does the phrase "Children tend to imitate their caregivers' speech patterns" affect the theory that suggests that children are born with universal grammar?
does not support it, bc that phrase implies that children learn via MODELLING and are not just born with it
why does effective nuclear charge increase across a period?
due to increasing nuclear charge with no accompanying increase in shielding effect
impression management
efforts to control impressions that others receive of us Self-disclosure, appearance, ingratation (flattery), aligning action, alter-casting
what is the source of ATP in RBCs?
glycolysis
What type of bond is cleaved by a lysozyme
glycosidic bonds
adding a third capacitor in series to a circuit with 2 capacitors in series already will do what to the total capacitance of the circuit and charge drawn from the battery
goes down
which bacteria kind is more receptive to antibiotics?
gram +
Which nucleoside has the largest molecular weight
guanosine
in titration flat part is
half equivalence point the equivalence point is where the line is vertical and the ph at that point if higher means there is a strong base weak acid and if its lower than 7 then its a strong acid mixed with weak base ---- its base because This is because the congugate base you form hydroxide after doing hydrolysis with water
Function of uncouplers
inhibit ATP synthesis --> body uses own fuel --> ↓ glycogen
3 types of enzyme inhibition
1) competitive 2a) non-competitive/pure 2b) mixed 3) uncompetitive
Inhibition of PFK by ATP is in an example of
1) feedback inhibition 2) allosteric inhibition
explain/list secondary messenger events of hormones:
1) hormone binds receptor on cell surface .˙. receptor changes shape 2) receptor interacts with G-protein*GDP 3) once it interacts, GDP becomes GTP 4) .˙. G-protein*GTP interacts with adenylate cyclase and activates it 5) the activated adenylate cyclase converts ATP to cAMP 6) cAMP activates the protein inside the cell whose effect is targeted
1 Pa = ________ N/m^2 = _____ kg/m.s^2
1, 1
what 3 hormones regulate the GI system?
1- gastrin: released in stomach - stimulates release of digestive juices (HCL + pepsinogen) + increases stomach motility to make chyme 2- secretin: released in duodenum as a result of chyme acidity - goes to pancreas and stimulates release of HCO3 to neutralize acidic chyme + goes to stomach to inhibit effects of gastrin 3- CCK: released in duodenum as a result of the fats in the chyme - goes to pancreas to stimulate release of pancreatic enzymes to help in the digestive process - goes to gallbladder and causes it to contract to release bile - inhibits effects of gastrin in stomach
the 4 special amino acids and why?
1- histidine: has a pKa of 6.5 .˙. it exists equally in a protonated and deprotonated form = good to have in an active site 2&3- proline & glycine = disrupt the secondary a-helix .˙. found at helix ends 4- cysteine = has a thiol group which forms disulphide bridges
male urethra
1- internal urethral sphincter 2- prostatic urethra 3-external US 4- spongy urethra
Prolonged fasting steps
1. phosphorylation / dephosphorylation 2. ↓ glycogen storage 3. protein breakdown (absorptive) 4. ketone bodies (starvation)
Distance between adjacent crests and troughs
1/2 wavelength
Virion size
100 nm (smaller than all eukaryotic cells)
Pregnancy
1st trimester: ↑ hCG & ↓ FSH ↑ Progesterone throughout
PH of the stomach is around
2
glycolysis produces ____ ATP molecules per 1 glucose molecule
2
rate determining steps can only involve how many molecules
2
what are n*isoprene terpenes called? 2 isoprene units = _______ 3 = ? 4? 5? 6? 8?
2 = monoterpene 3 = sesquiterpene 4 = diterpene 5 = sesterterpene 6 = triterpene 8 = tetraterpene
4 moles of NaCl are added to 4 L water where thy dissociate completely. What is the total molar concentration of solutes in the resulting solution
2M
What are the structural features possessed by storage lipids?
3 fatty acids ester-linked to a glycerol
palindromic sequence
4 base or 6 base
Steroid
4 fused rings: 3 cyclohexane & 1 cyclopentane
if JND is 12 pounds for a 10 pound weight what is the JND for a 20 pound weight
4 pounds. NOTE: JND RATION IS RELATIVE TO INITAL STIMULUS, NOT FINAL STIMULUS
a spring is compressed 2 inches then it is compressed more to 4 inches how much PE is increased?
4 times more because 2^2 displacement is squared
alpha decay
4/2 aka takes away 4 out of the mass and 2 out of the atomic number
In a laboratory population of Drosophila, all the males are XsY. Among the females, 15% are XiXi, 50% are XiXs, and 35% are XsXs. Assuming random mating, what proportion of male flies in the next generation will be XiY? A. 12% B. 30% C. 40% D. 65%
40% All the males in the next generation will acquire a Y chromosome form their male parent, so the contribution of the male can be ignored. All the XiXi females will have XiY sons, so 15% of the XiY flies in the next generation will come from this type of female. Half of the sons the XiXs females produce will be XiY. Since XiXs females make up 50% of the population, 25% of the males in the next generation will come from this type of female. non of the sons of XsXs females will be XiY. So 15+25=40%
How many chromosomes do humans have?
46 (23 pairs)
At what pressure can we say that the volume of the gas molecules is no longer negligible?
500 atm
self efficiency
= (loadxload resistance)/(effort x effort distance)
In the ABO blood group system in humans, if a person of type-B blood has children with a person of type-AB blood, what blood types could their children have? Type-AB, type-A, and type-B Type-A and type-B Type-B and type-AB Type-AB, type-A, type-B, and type-O
A person of type-B blood could be homozygous (BB) or heterozygous (BO). The question intentionally leaves this ambiguous. One way to answer this question is to draw Punnett squares. To account for both possibilities of the genotype of the type-B blood person, you will have to draw two Punnett squares- one for an ABxBB cross and one for an ABxBO cross. In an ABxBB cross, the possible genotypes are AB and BB. For an ABxBO cross, the possible genotypes are AB, AO, and BO. Since the A and B alleles are codominant, the possible blood types of the children are type-AB, type-A, and type-B.
What would a "proactive" antibody do as opposed to a "reactive" antibody?
A proactive antibody would prevent infection before it starts, usually by preventing antigen binding to target. Proactive usually better than reactive
Bohr Effect
Exercise (right shift): Resp ↓, ↓ O2, ↓ pH, ↑ CO2/H+ in blood, ↑ temp, ↑ 2,3-BPG Left shift: Resp ↑ , ↑ O2, ↑ pH, ↓ CO2/H+, ↓ temp, ↓ 2,3-BPG
Lipase
hydrolyzes lipids/fatty acids
Through which of the following blood vessels does blood travel most slowly? A. Capillaries B. The Aorta C. Arteries D. Veins
A. This question is more of a physics question than a biology question. We know that cross sectional area multiplied by blood velocity is constant throughout the human body. While capillaries are very tiny in comparison to the arteries and veins, there is an enormous number of them, giving them much higher functional cross-sectional area than the other vessels. Thus A is high for capillaries, implying that v must be low, thus capillaries is the correct answer. This question can also be answered using biology. Since capillaries are the only place where fluid exchange takes place, we know that blood in the capillaries must move slowly to properly oxygenate all of the tissues of the body.
Kiliani-Fischer synthesis is a method converting a monosaccharide into a monosaccharide with one more carbon atom. Because the mechanism is not stereospecific, two epimers are produced from each monosaccharide. If a sample of D-glyceraldehyde, a triose, were used and a series of Kiliani-Fischer syntheses were applied, what proportion of all hexoses would be glucose? A. 13% B. 50% C. 67% D. 100%
A. This question may be challenging but it is perhaps more convoluted than difficult. We're told that the synthesis will increase the carbon number by one, so we can conclude that a triose would convert to a tetrose. We're also told that this conversion is not stereospecific and produces two epimers, so from D-glyceraldehyde we will get 2 epimers of tetroses (each chiral carbon has only two options: R or S). Each tetrose will produce 2 more epimers of pentoses, so we get a total of 4 pentoses. Each pentose will further create two hexoses, yielding a total of 8 hexoses. Since glucose is an aldohexose, it will be 1 of those 8. And, since the conversions were not stereospecific, the presence of each hexose should be roughly equal, or 1/8 = 13%.
Which of the following colors of light has the lowest frequency? A. Red B. Orange C. Yellow D. Green
A. We are looking for the color that has the lowest frequency (or equivalently, the longest wavelength). Violet color has the smallest wavelength and largest frequency (thus why UV rays can cause a sunburn). Red light has the longest wavelength, and equivalently smallest frequency. Thus (A) is the correct answer.
Which of the following is a correct name for aspartic acid? A. 2-Aminobutanedioic acid B. 3-Aminoethanedioic acid C. 2-Aminoethanedioic acid D. 3-Aminobutanedioic acid
A. When naming things with carboxylic acids, the carboxylic acid usually takes the highest priority. Here, the structure has two carboxylic acids meaning that it will be a -dioic acid. Next, finding the carbon chain length just requires counting the carbons. Be careful here since the carboxylic acid carbons count in the total chain length. The chain length for aspartic acid is four, which means that it is butane; this eliminates B and C. The last piece of the puzzle is placing the NH₂, or amino, group. When assigning numbers, always choose the lowest possible. This means that the amino group is on the number 2 carbon.
When a strip of Cu is placed into H2O, no change is observed. However, when a strip of Cu is placed into a solution of HNO3, a gas evolves. What is the most likely identity of the gas? A. NO B. CO2 C. H2 D. O3
A. NO is evolved. Copper is oxidized and nitrogen is reduced.
Approximately how many moles of Al3+ are reduced when 0.1 faraday of charge passes through a cell during the production of Al? A. 0.033 mol B. 0.050 mol C. 0.067 mol D. 0.10 mol
A. a faraday is equal to one mole of electric charge. Because each Al ion gains 3 electrons, 0.1 faraday of charge will reduce 0.1/3 mols of aluminum, or 0.033 moles
A receiver is in a jet alongside another jet that is emitting a 2.0 x 10^6 Hz waves. If the jets fly at 268 m/s, what is the change in frequency at the receiver? A. 0 Hz B. .90Hz C. 1.79 Hz D. 3.58 Hz
A. because there is no relative motion between the jets (both traveling at same speed), there is no frequency shift
Why are the percentages of the change in frequency and wavelength much greater when sound wave are used instead of radio waves? A. sound waves travel more slowly B. sound waves have a much higher frequency C. sound waves have a much shorter wavelength D. interference in the atmosphere affects sound waves much more
A. doppler equation for frequency is delta f/f = v/c. delta f depends inversely on the speed of the wave in the medium in which it propagates, c. The vel of sound is much smaller than electromagnetic radiation, so for same relative vel, frequency and wavelength shifts are much greater for sound than radio waves.
how does ADH affect plasma clearance of a substance
ADH decreases plasma clearance because the decreased rate of urine output slows glomerular filtration rate and allows more time for reabsorption by the kidney
Squalene
AKA triterpene, and is the backbone of all steroids in our body. - squalene gets cyclicized into CHOLESTEROL in the LIVER
edema
Abnormal accumulation of fluid in INTERSTITIAL spaces of tissues.
The many steps of glycolysis all exist in a state of dynamic equilibrium between reactant and product concentrations. Which of the following actions does NOT affect the equilibrium position of a reaction? A. Adding or subtracting heat B. Adding or removing a catalyst C. Increasing or decreasing concentrations of reactants D. Increasing or decreasing volumes of reactants
Adding or removing a catalyst The equilibrium of a reaction can be changed by several factors. Adding or subtracting heat, choice (A), would shift the equilibrium based on the enthalpy change of the reaction. Increasing reactant concentrations would shift the equilibrium in the direction of the product, and the opposite would occur if reactant concentrations were decreased, eliminating choice (C). Changing the volume of a reactant would affect any reaction with gaseous reactants or products, eliminating choice (D). While adding or removing a catalyst would change the reaction rate, it would not change where the equilibrium lies.
Abnormal levels of what hormone would cause an increase in blood pressure that cannot be corrected by the kidneys
Aldosterone
Emission
Alpha: lose 2 protons. Helium. (Mass # - 4). (Atomic # - 2) Beta(+): Atomic # - 1 Beta (-): Atomic # + 1. Neutron --> Proton. Emit electron. Gamma: emits Photon. high energy decay. presence of kinases. ATP.
Inclusive fitness is used to explain what type of behavior?
Altruistic
Mental diseases
Alzheimer: ↓ acetylcholine Depression: ↑ Gluco & ↓ serotonin, dopamine, norepinephrine
In what phase of meiosis does nondisjunction occur?
Anaphase 1 or Anaphase 2
Order of reactivity
Anhydrides > Carbox acid + ester > Amide
Phosphatides
Any of a class of compounds that are fatty acid esters of glycerol phosphate with a nitrogen base linked to the phosphate group
Artery, Capillary, Veins
Artery: elastic, thick, smooth muscle Capillary: narrow, thin, gas/solute, endothelial turnover Vein: inelastic, thin, skeletal muscle
Trick for Bernoulli's Equation problem
Assume P1 = P2 b/c gauge pressure usually equals atmospheric pressure
Which of the following is NOT a granulocyte? A) Neutrophil B) Macrophage C) Eosinophil D) Basophil
B) Macrophage A granulocyte is a leukocyte that contains granules visible by microscopy, and a macrophage is not a granulocyte (choice B is correct). Neutrophils, eosinophils, and basophils are granulocytes (choices A, C and D are incorrect).
XCH₂COOH In the compound above, which of the following at "X" would result in the weakest carboxylic acid species? A. Cl B. I C. Br D. F
B. Any of the elements above at "X" would contribute inductive effects, drawing the electrons in the bond between O and H closer to oxygen. The greater the inductive effect, the more acidic the carboxylic acid. Thus, the least electronegative halogen species, Iodine, at "X" would produce the weakest acid since it would contribute the least inductive effect.
Which is more important in determining bond length? Polarity or atomic radii?
Atomic radii
Prostaglandin
Auto/para signal, REG (cAMP), INHIB (NSAID), Function: contract, sleep/wake, fever, pain
Stages of sleep
Awake (beta&alpha): alert 1 (theta): Light sleep 2 (theta): sleep spindle, k-complex 3/4 (delta): SWS, dreams, declarative memory, sleep disorders REM (beta): dreams, procedural memory, sleep disorders
An enzyme without its cofactors is called which of the following: A) Zymogen B) Apoenzyme C) Holoenzyme D) Coenzyme
B) Apoenzyme An enzyme without its cofactors is called an apoenzyme.
During which stage of sleep are research subjects likely to display theta waves on an EEG? A) Stage 1 B) Stage 2 C) Stage 3 D) Stage 4
B) Stage 2 Theta waves are found in stage 2 of sleep (choice B is correct; choices A, C, and D are incorrect).
Which of the following best approximates an ideal fluid? A. Water flowing in a river bed B. A gas moving at half its critical velocity C. A stationary container of oil D. Melted candle wax near the wick
B. Viscosity is related to how "thick" or "thin" a fluid is, or better stated, the amount of resistance to flow it provides. In general, gases demonstrate lower viscosity than liquids. Ideal fluids have no viscosity, so the best choice should demonstrate a low viscosity. Choice B, a gas, is therefore correct. Note that the container and the movement of the fluid were irrelevant to the question. Only the substance and atmospheric conditions (temperature and pressure) are important in determining viscosity, so choices A, C, and D are incorrect.
Two loops carry equal current (I) in opposite directions. If the loops are held in parallel and then released, which of the following best describes their expected behavior? You may ignore any influence of gravity. A. The loops will attract each other. B. The loops will repel each other. C. The loops remain in their same positions. D. The current in the top loop will gradually reverse its direction.
B. With this scenario, it is best to treat the loops as parallel wires with current going in opposite directions. And in such a case, these wires (loops) would repel each other because whenever current flows, a magnetic field is created around the wire, with a direction dictated by the right hand rule. If the currents were going in the same direction, the magnetic fields from the wires would be going in the same direction, and the wires would be attracted to each other. In the case we have (of currents going in opposite directions), the magnetic fields go in opposite direction and repel each other.
Lower leptin levels are part of the body's response to food deprivation. Based on this information, administering leptin to mice in the Ob1 group would most likely cause which of the following physiological changes to occur? A. Increased resistance to insulin B. Decreased plasma cortisol levels C. Increased appetite D. Decreased locomotor activity
B. Without leptin, mouse behavior resembles that of extreme starvation. Physiologically, this means elevated plasma cortisol, inability to effectively under thermogenesis, unrestrained appetite, and resistance to insulin. Therefore, administering leptin should reverse any of the above symptoms.
What is the molarity of pure acetone? (58 g/mol and 0.791 g/mL) A. 1.36 M B. 13.6 M C. 45.9 M D. 73.4 M
B. (0.791 g/mL)(1000 mL/L)(1mol/58 g)
If chromosomal duplication before tetrad formation occurred twice during spermatogenesis, while the other steps of meiosis proceeded normally, which of the following would result from a single spermatocyte? A. one tetraploid sperm B. four diploid sperm C. four haploid sperm D. eight haploid sperm
B. Because replication occurred twice instead of once prior to tetrad formation, each sperm would have twice the normal amount of DNA. As a result the sperm would be diploid instead of haploid.
What is the key enzyme in cholesterol metabolism?
HMG-CoA reductase -active when cholesterol ↓ & insulin ↑
Colchicine, an inhibitor of microtubule reorganization is most likely to what affect on the cell? A Prevention of nutrient diffusion through cell membranes B. Inhibition of leukocyte phagocytosis of cellular waste C. Inhibition of cellular waste formation D. maintenance of the pH optimum for most enzymes
B. Phagocytosis requires that the cell change shape dramatically as it surrounds and engulfs large extracellular particles. Microtubules are on of the cytoskeletal elements that help determine cell shape
Where does energy production take place in bacteria that can perform aerobic metabolism? Mitochondria Nucleus Inclusion Bodies Plasma membrane
Bacteria, like eukaryotes, rely on a concentration gradient to drive an ATP synthase molecule. Bacteria are prokaryotes, and do not have membrane-bound organelles. Energy production in bacteria takes place across the plasma membrane, with the gradient between the extra- and intracellular environment providing the appropriate concentration gradient.
At a given temperature, the resistance of a wire to direct current depends only on the: A. voltage applied across the wire B. resistivity, length, and cross-sectional area C. inductance, length and cross-sectional area D. resistivity, length, and capacitance
B. Resistance = resistivity x length/area
From which germ layer(s) do the tissues of the heart and blood vessels differentiate? A. Ectoderm B. Mesoderm C. ectoderm and mesoderm D. endoderm
B. The heart and blood vessels both differentiate from the mesoderm
Electrons in which of the following orbitals of Ti (electron configuration of [Ar] 4s2 3d2) participate in forming bonds with another substance? A. 2s B. 3d C. 4p D. 5f
B. Ti is transition element. Transition elements form bonds using electrons in their valence shells.
A ray of light in air strikes the flat surface of a liquid, resulting in a reflected ray an a refracted ray. The angle of reflection is known, what additional information is needed in order to determine the relative refractive index of the liquid compared to air? A. angle of incidence B. angle of refraction C. refractive index of air D. wavelength of the light
B. angle of refraction. To find the relative refractive index to air you need the incident and refracted angles. The angle of reflection = the angle of refraction so you need to know the angle of refraction. (refracted angle is the angle by which the wave enters te medium, θ2)
A sample of acid has a melting point of 189 C. If the sample is contaminated. what can be determined about the melting point of this mixture? A. the melting will have a broad melting range above 189 C. B. the mixture will have a broad melting range below 189 C C. the mixture will have a sharp melting point of 186 C D. the mixture will have a sharp melting point of 189 C
B. impurities always lower the melting point of the sample
Mechanica waves in a medium such as water function to transport: A. matter only B. energy only C. both matter and energy D. neither matter nor energy
B. mechanical waves are a local oscillation of material. only the energy propagates, the oscillating material doesn't move far from it initial equilibrium position
A far-sighted person can see objects clearly no closer than 300 cm away. What is the minimum distance from a plane this person must be to see his reflection clearly? A. 75 cm B. 150 cm C. 300 cm D. 600 cm
B. plane mirrors produce images behind its plane at a distance equal to the object distance infront of the plane. a person standing at a distance of 150 cm will focus at a distance 150 cm behind mirror and will be a total distance of 300 cm
When the current in a circuit is 1 x 10^-3 A, what power is dissipated as heat in the resistor with a resistance of 1 x 10^2 ohms? A. 1 x 10^-6 W B. 1 x 10^-4 W C. 1 x 10^-2 W D. 1 x 10^ -1 W
B. power dissipated as heat = I^2 x R
If one mole of each of the following undergoes a complete combustion, which compound requires the least amount of oxygen? A. C4H9OCH3 B. C2H5OH C. C4H9OC2H5 D. C5H11OCH3
B. the compound with the lowest carbon-to-oxygen ration will require the least amount of oxygen for combustion.
A gas that occupies 10L at 1 atm and 25 C will occupy what volume at 500 atm and 25 C? A. exactly 0.020 L B. somewhat more than 0.02 L because of the space occupied by the individual gas molecules C. somewhat more than 0.02 L because of the repulsion between the individual gas molecules D. somewhat more than 0.02 L because of the increased number of collisions with the sides of the container?
B. the ideal gas law makes the assumption that molecules have no volume. This assumption is adequate when the gas is at 1 atm, but when the pressure is increased to 500 atm the volume of the gase molecules is no longer negligible
2 rounds after transferring cells from one medium to another, what DNA weights will they have?
Half will be the weight of the first and half will be the weight of the second. NOTE: For even number of rounds, you don't have one strand of each (both strands will be one or the other). For odd rounds you do.
If a leak develops in the distillation apparatus, what would happen to the boiling points of the components inside?
Both would increase. Vapor pressure increases w/ increasing temperature, thus the boiling point of a liquid decreases as the pressure on the surface of the liquid decreases. If a leak develops, the surface pressure increases so the boiling point increases
Ribozyme vs Enzyme
Both: secondary structure (H-bonds), ↓ Ea, Ribozyme: can be cleaved by phosphodiesterase
Ronny's parents immigrated to America before he was born. Ronny has very few traces of his original culture. This is an example of: A) Culture lag B) Culture shock C) Assimilation D) Multiculturalism
C) Assimilation Assimilation occurs when an individual begins to lose characteristics of his or her previous culture and gain characteristics of the culture that he or she is in (choice C is correct). Culture lag describes the tendency of culture to lag behind technological innovations, thereby leading to tensions in society (choice A is incorrect). Culture shock describes the feelings of disorientation felt by an individual who experiences a new culture for the first time (choice B is incorrect). Multiculturalism occurs when individuals of different cultural backgrounds co-exist (choice D is incorrect).
Which waves would an EEG show for an awake and active individual? A) Delta B) Theta C) Beta D) Alpha
C) Beta Delta waves are experienced during stage 3 of sleep (choice A is incorrect). Theta waves are experienced during stage 2 of sleep (choice B is incorrect). Beta waves are experienced during wakefulness (choice C is correct). Alpha waves are experienced during stage 1 of sleep or relaxation (choice D is incorrect).
The lining of the digestive tract, the lungs, the liver, and the pancreas are formed from which germ layer? A. Ectoderm B. Mesoderm C. Endoderm D. Gastroderm
C. Ectoderm gives rise most notably to the skin and nervous tissue, the mesoderm to the excretory, heart and musculoskeletal tissue, and the endoderm to most internal organs. Gastroderm is a nonsense term.
Which phase of the cell cycle immediately follows mitosis? A. M B. S C. G1 D. G2
C. The cell cycle proceeds as follows: Mitosis (M) > G1 > S > G2 > M, which makes (C) the correct answer.
In an experiment students added two solutions containing reactants and a starch indicator. The addition of which of the following would not affect the results. A. solution A B. solution B C. Starch D. Additional base
C. Starch is not a participant in any of the reaction (as listed in passage)
Consider MTBE (C4H9OCH3) and ETOH (C2H5OH). What type of intermolecular interaction can ETOH undergo that MTBE cannot? A. van der Waals B. Dipole-Dipole C. Hydrogen bonding D. Covalent bonding
C. The -OH in ETOH give ETOH the capability of donating hydrogen bonds to water. MTBE is incapable of donating hydrogen bonds to water. Can't MTBE be Hydrogen acceptor??
Which of the following statements most accurately describes the solubility properties of fatty acid salts? A. they are soluble in polar media only B. They are soluble in nonpolar media only C. they can partially dissolve in both polar and nonpolar medi D. They are completely insoluble in both polar and nonpolar media
C. a fatty acid salt contains a long hydrophobic carbon chain that is soluble in nonpolar solvents, the salt contains a charged -CO2-Na+ head group which is hydrophobic and soluble in polar solvents
An object with a 15 g mass is immersed in benzene and suffers an apparent loss of mass of 5 grams. What is the approximate specific gravity of the object? Specific gravity of benzene = 0.7 A. 1.4 B. 1.8 C. 2.1 D. 3.0
C. buoyant force of an object immersed in a fluid is equal to weight of fluid displaced by the object. Apparent loss of mass = vol of liquid displaced. Ratio of object mass to fluid mass is 15/5 = 3. meaning specific gravity of object is three times the specific gravity of benzene (3 x .7 = 2.1) because the vol of object and displaced liquid are equal.
Tissue that is very active metabolically, such as skeletal muscle, contains large numbers of: A. nuclei B. Fat deposits C. Blood capillaries D. lymphatic vessels
C. metabolically active tissue requires a large supply of oxygen and produces many waste products. Such tissue need ample capillary blood flow to provide oxygen and to remove waste products
N2 has a lower boiling point than O2. which of the following best accounts for this difference? A. N2 is less reactive than O2 B. N2 is less electronegative than O2 C. N2 has a lower molecular weight than O2 D. N2 contains a triple bond, and O2 contains a double bond
C. neither has permanent dipole moment and thus increasing molecular mass increases the boiling point because it has more electrons and is more polarizable
Which of the following characteristics clearly marks fungi as eukaryotes? A. they have cell walls B. they contain ribosomes C. they contain mitochondria D. they exhibit sexual reproduction
C. one characteristic that distinguishes eukaryotic cells from prokaryotic cells is that eukaryotic cells contain membrane-bound organelles such as mitochondria
If a second liquid has twice the density of the first liquid. What is the pressure at a depth of 10cm for the second liquid if the pressure of the first liquid at 10 cm is equal to 400 N/m^2? A. 200 N/m^2 B. 400 N/m^2 C. 800 N/m^2 D. 1600 N/m^2
C. pressure in a liquid due to gravitational force of the liquid above a given depth is proportional to the density and the depth. For the same depth, the liquid with twice the density will create twice as much pressure as the first liquid.
What is the maximum possible number of steroisomers of a compound with 4 sterocenters? A. 4 B. 8 C. 16 D. 32
C. the number of steroisomers can be calculated using the formula 2^n, where n is the number of sterocenters in the molecules
How is glycogen synthase activated in liver & muscle?
Liver: prevent ↓ blood sugar (glucagon) Muscle: produce glucose (epinephrine/AMP)
Q = in Coulombs
CV capacitance and voltage
Cal/gram & RQ
Carbs: 4, RQ = 1 Proteins: 4, RQ = 0.8-0.9 Fat: 9, RQ = 0.7
Energy conversions in a battery powered resistive current
Chemical --> Electric --> Thermal
A chlorine atom can form I. A single sigma bond II. Four sigma bonds and three pi bonds III. Four sigma bonds and four pi bonds A. I only B. I and II only C. III only D. I, II, and III
Chlorine is typically found with a single sigma bond to another compound (e.g. HCl, or CCl₄). However, chlorine can also form multiple oxides (hypochlorite, chlorite, chlorate, and perchlorate). Each of these affects the number of sigma and pi bonds that the chlorine has made; perchlorate would be a chlorine bonded to four oxygen atoms, three of which are double bonded and one of which is single bonded (four sigma bonds and three pi bonds). Nonetheless, for chlorine to form four sigma bonds and four pi bonds, it would require 8 valence electrons. Since chlorine has only 7 valence electrons, option III will not form.
The triterpene squalene is a precursor to which class of biological molecules?
Cholesterol
Your trachea have short hair-like cell process that move the mucus. What is the name of these hair like structures and which cytoskeletal elements form them? A. Cilia, microfilaments B. Villi, microfilaments C. Villi, microtubules D. Cilia, microtubules
Cilia, microtubules Villi are macroscopic foldings of tissue Microvilli are foldings of the cell membrane that increase the surface area of cell but are not responsible for movement Cilia are eyelash like structures derived from microtubules, they are responsible for creating motion outside the cell.
Elemental analysis of a compound shows that it is composed of 85% Carbon and 15% Hydrogen by mass. What is the most likely identity of the compound? A. C₃H₆ B. C₃H₈ C. C₄H₈ D. Impossible to determine with the information given.
D. This question is impossble to answer without having the total mass of the compound. Because only a proportion is given, there are a number of different compounds that could fit into the proportion. For this particular question, A and C are both plausible as all compounds of empirical formula C_nH_2n will work.
How to assess whether a behavior is modeled or learned
Make a biographical sketch of patient's life up until the point of the study
structure functionalist
Manifest vs lantent (unintended conseq) functions
A stationary receiver detects a change in frequency of the signal from a jet flying directly from it at 300m/s. Which of the following receivers will detect the same change in frequency from a jet moving away at 600m/s? A. receiver moving at 900m/s in opposite direction as jet B. receiver moving at 300m/s in opposite direction as jet C. stationary receiver D. a receiver moving at 300m/s in same direction as the jet
D. frequency of doppler effect depends on the relative motion of the source and detector. Relative velocity is additive when objects are moving at each other and subtractive when objects are moving in same direction of each other
At the end of a person's hospital stay, a few E. coli cells remained in the patient's colon, even though he was taking antibiotics. These cells were most likely present because: A. the antibiotics caused drug-resistance mutation to occur in bacterial DNA B. the bacteria in the patient developed an immune reaction to the antibiotics C. the patient's colon cells became increasingly resistant to the antibiotics D. chance mutation in a few E. coli before treatment made these cells and their descendants antibiotic-resistant
D. mutation which make cells drug resistant are rare. Antibiotics (as in choice A) are unlikely to be the cause of genetic mutation
The fundamental, resonant wavelength of a pipe open at both ends that is 1 m long and 0.1 m in diameter is: A. 0.1 m B. 0.2 m C. 1.0 m D. 2.0 m
D. pipes and tubes have their resonant wavelengths when standing waves develop. An open pipe has its fundamental, resonant wavelength twice the length of the pipe. Wavelength is independent of the diameter
An astronomer observes a hydrogen line in the spectrum of a star. The wavelength of hydrogen in the lab is 6.563 x 10^-7 m, but the wavelength in the star's light is measured at 6.5618 x 10^-7 m. which of the following explains this? A. the star is moving away from earth B. the wavelength of the light the star is emitting changes constantly C. the frequency of the light the star is emitting changes constantly D. the star is approaching earth
D. the wavelength of the star is smaller because of the doppler shift associated with approaching relative velocity between star and earth. wavelength would get larger that lab if star was moving away form earth
Central Dogma of Molecular Biology
DNA -> RNA -> Protein -DNA to DNA = replication -DNA to RNA = transcription -RNA to protein = translation
Transcription factors
DNA binding domain that allows it to bind to regulatory nucleic acid sequences in gene to alter transcription
Aldosterone stimulates Na+ reabsorption by the kidneys. What changes in the blood volume and pressure would be expected as a result of aldosterone deficiency? A. Increased volume and increased pressure B. Decreased volume and decreased pressure C. Increased volume and decreased pressure D. Decreased volume and increased pressure
Decreased volume and decreased pressure An aldosterone deficiency would result in lower Na+ reabsorption in the kidney. Because water passively follows Na+ during reabsorption in the kidney, less Na+ reabsorption would result in less water reabsorption in the blood stream. This would cause a reduction in blood volume and pressure.
Relationship between speed of transmitter away from receiver and wavelength of received signal
Directly proportional delta lambda/ lambda = v/c
coupling constant
Distance between the peaks of a multiplet
autonomic nervous system (ANS)
Divided in symp & parasymp. Interceptive awareness.
How does electric field depend on the difference in length between anode and cathode?
E = (V -IR)/L
Energy of photons emitted
E = hf - work function
cell potential (Ecell) equation
E cathode - E anode (IF using the reduction potential TABLE) if using the 2 half rxns = E anode + E cathode *NOTE: if you're using the reduction table, you NEVER switch the sign when finding the Ecell even if the equation is flipped!*
Bases vs amino acids
Each amino acid is encoded by 3 bases
Reduction potential
Ecell = E (red, cathode, more +) - E (ox, anode, more -) -Voltaic: Ecell has to be + -Concentration: Ecell has to be 0
Conductors
Electric field is 0 when free electrons (carry current) arrange themselves on surface so Electric field they produce cancels any external external field
What type of was is an electromagnetic signal, and what type of wave is a sound wave?
Electromagnetic waves are transverse, sound waves are longitudinal
Absorption of UV light by organic molecules always results in what process
Excitation of bound electrons
Absorption of UV light results in:
Excitation of bound electrons
what is used for moving lipids between leaflets because theres a high entropy cost to moving them from one side of the membrane to the other
Flipases for the leaflets son
Why would a molecule fluoresce during size-exclusion chromatography?
Fluorescent dye is trapped inside
Circulatory system shunts
Foramen ovale: R --> L atrium (Bypass lung) Ductus art: Pulm artery --> Aorta (Bypass lung) Ductus ven: Umbilical vein --> Inferior vena cava (bypass liver)
Peptide bond
Form it = water molecule lost (byproduct)
Infusion of what hormone would prevent brain injury in newborns exposed to high glucose levels during fetal development
Glucagon
Gluconeogenic vs ketogenic amino acids
Gluco: ALL amino acids except for LEU/LYS Keto: LEU/LYS
response bias
anything in a survey design that influences responses AKA if the wording of the Q influences you to pick a specific answer
Portal systems
Hepatic: Gut --> Liver (hepatic portal vein) Hypophyseal: Hypothalamus --> Anterior pituitary Renal: Glomerulus --> Vasa recta (efferent arteriole)
heterochromatin vs. euchromatin
Heterochromatin = dense, silent, last to replicate Euchromatin = loose, active
What are ways in which chromatin is modified?
Histone acetylation (↑ access), DNA methylation (↓ access) -Both ↓ transcrip and ↑ heterochromatin
Types of control
Hormonal: metabolic, systemic, covalent Allosteric: local or systemic
is voltage an intensive or extensive property? what does that mean?
INTENSIVE the amount/moles DOESNT MATTER! the voltage is the same
Solution equilibria
IP > Ksp : supersat & precipitate IP < Ksp: unsat & dissolves IP = Ksp : saturated & no change in [ ]
functional analysis
apply laws of operant conditioning to establish r.s. between stimuli & responses
When is insulin secreted by pancreas?
In response to ↑ blood glucose [ ]
Where does polypeptide cleavage happen
In the endomembrane system
Where is bile produced and stored?
In the liver and stored in the gall bladder
Virus
Includes: DNA/RNA, viral enzymes, proteins
A hiker becomes lost and has no drinking water for 2 days. At the end of this time, which of the following changes in hormone production would be expected to be significant in this individual? A. Decreased glucocorticoid secretion B. Decreased aldosterone secretion C. Increased insulin secretion D. Increased antidiuretic hormone secretion
Increased antidiuretic hormone secretion Antidiuretic hormone (also called ADH or vasopressin) secretion increases in times of stress and when the osmotic pressure in the blood stream increases as it would if the blood became more concentrated due to water loss.
What would be the most effective method of increasing the amount of water lost through the skin
Increasing environmental temperature NOT decreasing salt consumption
2 types of systems
Inducible: lac operon, ↑ transcrip Repressible: trp operon, ↓ transcrip
There are two main types of neurotransmitter receptors. Which of the following statements about receptors accurately describes how they function? Ionotropic neurotransmitter receptors move more slowly than metabotropic neurotransmitter receptors. Metabotropic neurotransmitter receptors move more slowly than ionotropic neurotransmitter receptors. Ionotropic neurotransmitter receptors activate a second messenger inside the neuron. Metabotropic neurotransmitter receptors directly allow ions to pass through the membrane.
Ionotropic neurotransmitter receptors are the type of receptor that directly allows ions to pass through the membranes. Metabotropic neurotransmitter receptors are the type of receptor that activate a second messenger inside the neuron. Metabotropic neurotransmitter receptors move more slowly than ionotropic receptors, but their results may be larger and more widespread.
To keep current constant during a discharge cycle, what must happen to the resistance?
It must be continuously decreased
Why does light travel more slowly through an optically dense medium than through a vacuum?
It's absorbed and re-emitted by the atomic structure of the optically dense medium
Kw=
Ka*Kb = [H+]*[OH-]
The products of the liver and pancreas participate in what type of digestion? Please choose from one of the following options. Mechanical and chemical, respectively Both mechanical Both chemical Chemical and mechanical, respectively
Mechanical digestion separates molecules of a substance, without changing its chemical properties, and is also known as physical digestion. Chemical digestion breaks intramolecular bonds and changes the "identity" of a substance. Bile from the liver is involved in emulsification of fats, a mechanical process, while pancreatic enzymes chemically cleave apart macromolecules.
polypeptide pattern
N-C-C-N-C-C
Does SDS page reduce disulfide linkages?
NO only reduces subunits into monomers
Does Km change with [E]?
NO! Vmax does though
Do nuclear proteins have signal sequence domains?
NO. Only proteins directed toward secretory pathways have these. Nuclear-directed proteins have nuclear localization domains instead
which of these is best for oxidizing a rxn? explain why: H2SO4, PCl3, NaClO3, NaBH4
NaClO3 H2SO4 is a strong acid and would protonate rather than oxidize NaBH4 is used for reduction PCl3 is known to convert carboxylic acids into acid halides Choice B is correct since it is a mild oxidizing agent
What type of western blot should you use to determine protein function
Native only
If an artery that supplies blood to a lung lobe was blocked but ventilation to the lobe was unaffected, how would alveolar gas partial pressures change? A. Both PO2 and PCO2 would increase B. Both PO2 and PCO2 would decrease C. PO2 would increase and PCO2 would decrease D. PO2 would decrease and PCO2 would increase
PO2 would increase and PCO2 would decrease If the blood flow to an alveolus were blocked there would be no flow of hemoglobin-rich red blood cells to take away O2 and no influx of CO2 from the blood.
Would an increase in the level of plasma aldosterone be expected to follow ingestion of excessive quantities of NaCl? A. No; aldosterone causes Na+ reabsorption in the kidney tubules B. No; aldosterone causes Na+ secretion by the kidney tubules C. Yes; aldosterone causes Na+ reabsorption by the kidney tubules D. Yes; aldosterone causes Na+ secretion by the kidney tubules
No; aldosterone causes Na+ reabsorption in the kidney tubules Aldosterone, which is produced in the adrenal cortex, causes Na+ reabsorption by kidney tubules. Such a mechanism decreases Na+ levels in the urine. The steroid aldosterone does not cause Na+ secretion into the urine. Because the ingestion of excessive NaCl would trigger Na+ secretion into the urine, plasma-aldosterone levels would not increase. Rather, the body would rely on those homeostatic mechanisms that excreted the excess Na+.
Superoxide
O2 -1 (-1/2 oxidation state)
Suppose that CH4(g)
O2(g) --> CO2(g) + H2O(g) with a total pressure of 1.2 torr. What is the partial pressure of H2O(g)? A. 0.4 torr B. 0.6 torr C. 0.8 torr D. 1.2 torr + C. 0.8 torr. ALWAYS BALANCE EQUATION!!! CH4 + 2O2 --> CO2 + 2H2O. partial pressure of H2O is 2/3 of total pressure = 0.8 torr
Learning technique
Operant cond: + reinforcement & punishment Classical cond: Uncond stimulus & response --> learning
psychosexual development
Oral (Ego develops, 0-1 yrs), Anal (1-3 yrs), Phallic (superego develops, 3-6 yrs), Latency (6-puberty), Genital (puberty - adult)
OIL RIG
Oxidation is losing electrons Reduction is gaining electrons
Production of which of the following hormones will be inhibited by the administration of dietary calcium to prevent osteoporosis? A. Growth hormone B. Calcitonin C. Thyroid hormone D. Parathyroid hormone
Parathyroid hormone, which is inhibited by high levels of calcium. Mnemonic for which hormone puts calcium into bone and which gets rid of it: Calcitonin-in parathyroid-rid
When an electrode of Au(s) is placed into a solution of PbSO₄, no precipitate of Pb forms on the surface of the electrode. Which of the following can be concluded from this information? A. The reaction Au
Pb²⁺ → Au⁺ + Pb is spontaneous. B. The E° of the reaction setup is negative C. An increase in the PbSO₄ would cause Pb²⁺ to plate onto the electrode. D. Reversal of the setup with a solid Pb electrode and aqueous Au would not have Au precipitate onto Pb. + B. The reaction shown is nonspontaneous because no reaction occurs as it is set up. Spontaneous reactions have a positive value for E° - this reaction will have a negative E° value and a positive value for ΔG. Increasing the concentrations will not drive the reaction in the reverse as it is driven by electrochemical potential and not an equilibrium reaction governed by Le Chatelier's principle. Reversal of the setup would reverse the E° and should have Au plate onto the Pb electrode.
Which type of membrane protein is most likely to be a hormone? A. Lipid-bound protein B. Peripheral protein C. Integral protein D. Steroid
Peripheral protein Hormones move through the circulatory system, acting as signaling molecules to specific organs/cells. A steroid is not a membrane protein. An integral protein can not easily leave the cell membrane and would therefore be a poor signaling molecule. Lipid-bound proteins remain within the phospholipid bilayer by the fatty acid tails of phospholipids. They would also be poor signaling molecules. Peptide hormones like insulin and growth hormone interact with integral protein receptors in cell membranes. These hormones can be considered peripheral membrane proteins.
Sound
Pitch (frequency), Loudness (intensity), Intensity (amplitude), Amplitude (volume)
Nucleus discoveries
Plank: quantum (energy diff) between levels Bohr: surrounded by electrons w/ energy levels Rutherford: dense & +
How would a patient with Alzheimer's Disease perform on verbal fluency and negative priming tasks
Poor performance on both
in order for a substance to dissolve delta S must be negative or positive
Positive
Purines vs. Pyrimidines
Purines (2 rings): Adenine, Guanine Pyrimidines (1 ring): Cytosine, Thymine, Uracil -GC (are more stable & contain more 3-H) G = 2 donors & 1 acceptor C = 1 donor & 2 acceptors
Sphincters/Valves
Pyloric: small intestine to stomach Cardiac: esophagus to stomach Iloceleal: small intestine to cecum Thoracic: lymphatic system to cardiac system
Pyranose & Furanose
Pyranose: 6 membered ring Furanose: 5 membered ring
Given a parallel circuit with three resistors, which of the following formulas describes the equivalent resistance? A) 1/Req = R1
R2 + R3 B) 1/Req = 1/R1 + 1/R2 + 1/R3 C) Req = R1 + R2 + R3 D) Req = 1/R1 + 1/R2 + 1/R3 + B) 1/Req = 1/R1 + 1/R2 + 1/R3 Choice B shows the correct formula for a parallel circuit. Req for a circuit in series would be calculated using the formula from answer choice C.
What are the 3 forms of heat transfer in which energy is lost from the body?
Radiation, Conduction, Convection
Micro RNA (miRNA) primarily aids in transcriptional and post-transcriptional regulation by which method? RNA editing via deamination of specific DNA sequences Gene amplification through binding directly to critical DNA promoter regions Cleavage of telomeres from 5' termini Gene silencing through translational repression or target degradation
Recall that microRNA does bind directly to mRNA, however it does not bind to promoter regions. miRNA has no role in RNA editing or cleavage of telomeres. The role of miRNA is to cause repression or degradation of the target through mRNA binding.
Which type of membrane receptor protein best describes receptor tyrosine kinases? A. G-Protein coupled receptor B. Intracellular receptor C. Enzyme-linked receptor D. Ligand-gated ion channel C. Enzyme-linked receptor
Receptor tyrosine kinases are integral membrane proteins that relay a "message" from the extracellular side of the cell to the intracellular side of the cell. Upon activation, receptor tyrosine kinases dimerize and phosphorylate tyrosine residues on each other's tails. This enzymatic kinase action makes receptor tyrosine kinases enzyme-linked receptors
How does stereotype threat relate to optimal arousal theory
Reminding people of a negative steroetype associated with their identity increases arousal beyond what is normal and leads to poor performance
Michealis-Menten Kinetics
Req: Initial velocity under steady state cond, pH constant, [ ] enzyme < substrate,
who's double bond is longer and more unstable S2 or O2
S2 because it is below O2 but in the same valence shell configuration do to a larger electron cloud its bonds are longer
Cardiac impulse pathway
SA node (R atrium) --> Atria --> AV node --> Bundle of HIS --> Purkinje fiber --> Ventricles
Which type of memory is NOT affected by aging
Semantic/Crystallized : ability to achieve general info
amino acids that can be phosphorylated
Ser, Thr, Tyr
polar amino acids
Serine, Threonine, Cysteine, Tyrosine, Asparagine, Glutamine
What would be the results of complete removal of the parathyroid glands? A. Severe neural and muscular problems due to deficiency of calcium in the plasma B. An increase in calcitonin production to compensate for calcium deficiency in the plasma C. A drastic change in the ratio of mineral to matrix tissue in bones D. Calcification of some organs due to accumulation of calcium in the plasma
Severe neural and muscular problems due to deficiency of calcium in the plasma Removal of the parathyroid gland would lead to hypocalcemia, a condition of low blood calcium, resulting from the lack of parathyroid hormone. This would cause increased neuromuscular excitability because of the change in membrane potential, which under normal physiological conditions, is partially kept in balance with the extracellular calcium.
What type of analysis maps relationships among a series of individuals?
Social Network analysis
What sociological perspective is most likely to supplement the biomedical approach to disease treatment
Social epidemiology
The cells type in the male reproductive system that is most analogous to the female ovum is the: A. Spermatogonium B. Primary spermatocyte C. Spermatid D. Spermatozoon
Spermatozoon The mature ovum is the female gamete that has completed meiosis and contains the haploid number of maternally derived chromosomes. This makes it most analogous to spermatozoa, the mature male gametes that contain the haploid number of paternally derived chromosomes.
Conformation
Staggered: 60 deg, anti (180 deg), gauche (60 deg) Eclipsed: 120 deg
Acidic amino acids (- charged)
aspartic acid, glutamic acid
Blood pathway
Superior vena cava --> R atrium --> R ventricle --> Pulm artery --> Lungs --> Pulm vein --> L atrium --> L ventricle --> Aorta --> Artery --> Arterioles --> Capillary --> Venule --> Veins
Where is visual radiation located?
Temporal & parietal lobe
Which of the following is NOT a function of the 5' terminus of mRNA? Protects the mRNA from degradation Regulates nuclear export of mRNA Promotes ribosomal binding for translation Promotes polyadenylation
The 5' terminus does, in fact, protect mRNA from degradation. The 5' terminus is required for ribosomal binding, and regulates nuclear export of mRNA. However, the 5' terminus has no role in polyadenylation of the 3' terminus.
what are the aspects of gender differentiation, and what is NOT?
aspects: - social differences - cultural differences - value/attitude differences NOT: biological differences
What do both controlled & automatic processing have in common?
associated w/ encoding memory
Which of the following statements about the systemic effect of bacterial cells are true? A. Gram-negative bacteria are more likely to cause systemic effects because their outer membrane protects them from several antibiotics, making treatment more difficult. B. Gram-positive bacteria are more likely to cause system effects because the peptidoglycan in their cell walls is tough and hard for medicine to penetrate. C. Gram-positive bacteria are more likely to cause systemic effects because the lipopolysaccharide (LPS) in their membranes can act as a toxin to the circulatory system. D. Gram-negative bacteria are more likely to cause systemic effects because their lack of an outer membrane means they can more quickly infect host cells.
The cell envelopes of gram-negative bacteria have more layers than those of gram-positive bacteria. Gram-negative bacteria are considered to be more dangerous, because components of the outer membrane make them more resistant to antibiotics and the host's immune system. Additionally, the lipopolysaccharide found in its outer membrane is an endotoxin that damages the host.
Which of the following statements correctly describes the distinction between the exocrine and endocrine portions of the testis? A. The exocrine portion secretes only peptides; the endocrine portions secretes only steroids B. The exocrine portion releases its products into ducts; the endocrine portion releases its products into the blood C. The exocrine portion secretes only cellular elements; the endocrine portions secretes only chemical substances D. The exocrine portion is the target tissue for the products of the endocrine portion
The exocrine portion releases its products into ducts; the endocrine portion releases its products into the blood
What is the pressure of gas within the alveoli at the peak of inspiration, just before expiration, relative to that of atmospheric air? Less than atmospheric air Cannot be predicted without more information Greater than atmospheric air The same as atmospheric air
The flow of air (and all gases) is determined by pressure gradients. Air flows from areas of higher pressure to lower pressure. During inspiration, the diaphragm contracts which generates a negative pressure within the alveoli, which draws air into the lungs. During expiration, the elastic force of the thoracic wall and the alveoli themselves exert a positive pressure on the air within the alveoli. This pressure is greater than that of atmospheric air, and the air flows out of the lungs. At the peak of inspiration or expiration, the airflow momentarily stops. However, the airway is still open to the atmosphere. The halt of airflow is because the alveolar pressure is 'zero' relative to the atmosphere. The pressure within the alveoli at the peak of inspiration is the same as atmospheric air.
In a bacteria possessing the lac operon, which of the following occurs when glucose is low and lactose is abundant? Beta-galactosidase acetylases the operon Lactose permease cleaves lactose to glucose and galactose Lactose metabolism is increased by lactose binding to the operon Transport of lactose into the cell is enhanced
The lac operon contains genes necessary to enhance lactose metabolism. Cleavage of lactose is carried out by the beta-galactosidase encoded for by lacZ, not by lactose permease. When glucose is low but lactose is readily available, the lac operon is activated, enhancing transport of lactose into the cell as well as lactose utilization.
The partial pressures of carbon dioxide pCO2 and oxygen pO2 in the atmosphere at sea level are 0.3 mmHg and 160 mmHg respectively, but the partial pressures of these gases in blood leaving the lungs are 40 mmHg pCO2 and 95 mmHg pO2. What factor most likely accounts for this difference? CO2 end subscript is less soluble in the blood than O2 O2 penetrates more deeply into small airways than CO2 CO2 penetrates more deeply into small airways than O2 CO2 is more soluble in the blood than O2
The lungs do not mechanically discriminate between gasses. Both carbon dioxide and oxygen 'penetrate' throughout the entire lung. Henry's law states that the amount of gas that dissolves in a given liquid is directly proportional to the partial pressure of the gas in equilibrium with that liquid. If the only factor influencing dissolved gas concentrations is the partial pressure of the gas in the air in contact with the liquid, then we would assume that the ratio of oxygen to carbon dioxide would be equal both within and outside of the liquid. However, if a given gas were more soluble in a given liquid, a greater proportion of the gas could be dissolved within that liquid. CO2 is more soluble in the blood than O2
purpose of extrinsic longula muscles?
elevate, depress, retract tongue
affective
emotional part of additude
Which of the following will increase lymph flow? Decreased interstitial fluid colloid osmotic pressure Decreased cardiovascular capillary permeability Increased plasma colloid osmotic pressure Elevated cardiovascular capillary pressure
The rate of lymph flow is proportional to factors that tend to pull liquid out of the circulatory system and into the interstitial spaces of tissue. Fluid moves from regions of high pressure to low pressure; Elevated cardiovascular capillary pressure will cause fluid to move out of capillaries, to regions of lower pressure. Elevated capillary pressure will increase lymph flow. The lymph circulatory system is an open system; its purpose is to take up fluid from the interstitial space and transport it to the blood circulatory system. has valves to prevent backflow
Why is it necessary for experimenters studying the TCA cycle to determine the activity of complexes independent of one another?
The reactions catalyzed by the complexes are coupled to one another
Why is tagging an mRNA transcript NOT useful for determining localization of a protein in the cell
The tag would be expected in the cytoplasm (where the riboosomes are) and therefore wouldn't tell where the protein acts in the cell
Scientists isolate the lymph fluid from the right thoracic duct of a fasted ( ~24 hours) experimental animal 20 minutes after a meal. After chemical analysis, they find a high concentration of fatty acid ( ~2% of total volume) and no detectable amounts a free carbohydrates: what does such data indicate about the composition of the meal? The meal contained carbohydrates but not fats No conclusions can be drawn regarding the fat or carbohydrate content of the meal from this data The meal contained fats, but no conclusion about carbohydrates is warranted from the data The meal contained fats but no carbohydrates
The vast majority of ingested fats are absorbed from the digestive tract by the lymphatic system and enter the systemic circulation through the thoracic duct. Carbohydrates enter the systemic circulation at the hepatic portal vein; they do not travel in the lymphatic system. The data suggest that the meal contained fats, but no conclusion about carbohydrates is warranted.
Translational vs Rotational equilibrium
Trans: free fall, constant velocity, no acceleration, Net force = 0, Fgravity & Fair are equal in magnitude Rotational: constant angular velocity (0) & absence of net torque
A drug that increases the risk of tubal pregnancy is most likely to inhibit which of the following actions? A. Contraction of the uterus B. Secretion of follicle-stimulating hormone C. Onset of menstruation D. Transport of the ovum from ovary to uterus
Transport of the ovum from ovary to uterus The main reason for ectopic pregnancy is the failure of the fertilized egg to be transported from the oviducts to the uterus.
which groups are more stable, triads or dyads?
Triads
what is the main function of bile?
emulsify fats, aka make them easier to absorb
Diabetes symptoms and explanations
Urination Fatty acid and protein catabolism --> weight loss and fatigue Sweet tasting urine APPETITE LOSS IS NOT A SYMPTOM
Lesions
Ventromedial hypo: hyperphagia (can't stop eating) Lateral hypo: anorexia (never feel hungry) Anterior hypo: asexuality Amygdala: hypersexuality
Mechanical Work by an elastic force
W = 0.5kx^2 = 0.5fx
Power units
Watt, J/s, ft*lb/s, kgm^2/s^3
Which of the following statements regarding fetal circulation is FALSE? A. In the umbilical cord, there are more arteries than veins. B. The foramen ovale is the only shunt that connects two chambers of the heart. C. Blood flow in the ductus arteriosus is from the aorta to the pulmonary artery. D. The ductus venosus is the only shunt that bypasses the liver.
[C] is the correct answer. Blood flow in the ductus arteriosus is from the pulmonary artery to the aorta. The direction of flow is determined by the pressure differential between the right side of the heart (and pulmonary circulation) vs. the left side of the heart (and systemic circulation). Unlike in adults, the right side of the heart is at a higher pressure during prenatal life than the left side, so blood will shunt from the pulmonary circulation to the systemic circulation through both the foramen ovale and ductus arteriosus.
phosphodiester bond
a chemical bond joining successive sugar molecules in a polynucleotide
conditioned response
a learned response to a previously neutral stimulus
Zwitterion
a molecule or ion having separate positively and negatively charged groups
unconditioned stimulus (US)
a stimulus that elicits a response, such as a reflex, without any prior learning
self-actualization
according to Maslow, the ultimate psychological need that arises after basic physical and psychological needs are met and self-esteem is achieved; the motivation to fulfill one's potential
Use of histine tagging and a nickel column imply what type of chromatography
affinity chromatography
1/2 life
amount of time it takes for 1/2 of radioactive nuclei to decay into daughter nuclei
amphipathic vs amphoteric
amphipathic: has both hydrophilic and hydrophobic regions amphoteric: can act as both an acid and a base
Proline
amphoteric, BL base, form peptide bonds, ↓ stability of B-pleated sheets (no H bonding)
Amyloid
an abnormal protein present in Alzheimers resulting from misfolding of the protein
what's the difference between gram
and gram - bacteria? + gram + : has one THICK outer peptidoglycan layer and a THIN inner plasma membrane gram - : has a THICK outer membrane, a thin peptidoglycan layer, and an inner plasma membrane
conflict theory
anger or dissatisfaction based on inequality
disorder - borderline personality
attention seeking almost not a real
self effacing bias
attribute success to external factors
how do we find the isoelectric point of a polypeptide/aa?
average the pKas of the charged groups
biological perspective
based on biological inheritance
social contructionism
based on choices
social cog. perspective
based on expectattions of others
micheael menton kinetics are
based on there is one active site capable of binding substrate
how does stuff escape the glomerulus?
bc the blood vessels are made up of endothelial cells that are FENESTRATED
when a protein goes from a native structure to another one, what are H,S, and G signs?
bc the native structure is the most stable + lowest energy, changing the structure will make it more disorganized, take energy to go to that state .˙. all positive
why is this phrase wrong? "In eukaryotes, the promoter region is the start point of transcription and contains a binding site for RNA polymerase that can be modified by repressors and enhancers"
bc the promoter region is only where the RNA polymerase BINDS, NOT where transcription starts. transcription starts downstream of the promoter region. typically, repressors/activators are located between the 2
what is the ideal growth conditions for E.Coli?
bc they exist inside human colon: 37C˚, contineous shaking
Why do women get more UTIs than men?
bc women have a shorter urethra
step up is usually
before the transformers and step down is usually after
How is Na+ reabsorbed?
by primary active transport using ATP 1- lumen ===> epithelial: diffusion using Na channels 2- epithelial ===> interstitial: Na/K pump 3- interstitial ===> blood: diffusion
what element is most likely to be found bound to a protein in the body
calcium
which muscles types have striated muscle fibers
cardiac and skeletal
2 primary factors that determine BP
cardiac output & resistance to blood flow
blood pressure =
cardiac output * total peripheral resistance
hepatic vein
carries blood from the liver - oxygen + nutrient poor
G6P dehydrogenase
catalyzes conversion of G6P --> 6-Phosphogluconoate
higher ph amino acids migrate to the negative cathode or positive anode
cathode
reduction occurs at the ___ while oxidation occurs at the ___
cathode, anode
when a molecule is said to be "antigenic", it means:
causes antibody production/ causes an immune response
the colon/large intestine is divided into:
cecum ----> spending colon -----> transverse colon ----> descending colon ----> sigmoid colon
Sertoli cells
cells found within the seminiferous tubules that provide metabolic support for the spermatids
difference between membrane protein CHANNELS vs. CARRIERS
channels: don't require ATP + usually go with the gradient carrier: carry molecules across the membrane + can use ATP
alveoli don't have
cilia
cis vs trans fatty acids
cis- the 2 carbons d-bonded are on the same side trans - the 2 carbons are on opposite sides
Lipoic acid
co-factor for pyruvate dehydrogenase complex
FAD
cofactor oxidant
What component of attitudes are assessed by self report data
cognitive
aspects of additude
cognitive behavioral affective' emotional
convex lense
converging corrects far sightedness (can't see close up)
what hormone is a modulator of carbohydrate metabolism
cortisol
is current positive or negative? how does that affect electrons?
current (I) is positive .˙. electrons go in the opposite direction eg: if current goes clock-wise, electrons go anti-clockwise
step up transformers increase the voltage while reducing the
current (power remains constant)
which amino acid forms a di-sulfide bridge?
cysteine
when is it cystine vs. cysteine?
cysteine = no bridge = in reducing environments (inside cell) cystine = disulfide bridge = oxidizing environments (extracellular)
what carries out detoxification in the liver?
cytochrome p450 enzymes
in a parallell circuit with two resistors removing resistor two would do what to the current drawn from the battery
decrease it
in a series circuit with 2 resistors adding a third resistor in series would do what to the current drawn from the battery
decrease it
which of the following will be the result of a ph increase in the mitochondrial inter membrane space?
decrease proton gradient and decreased atp
in a series circuit with 2 resistors adding a third resistor in series would do what to the voltage drop and current through resistor 1
decrease voltage drop and current
The chemical valinomycin inserts into membranes and causes the movement of K+ into the mitochondria. Based on the ETC, if mitochondria are treated with valinomycin, the rate of ATP synthesis in the mitochondria will most likely: A. decrease, because the K+will compete with protons at the active site on ATP synthetase B. decrease, because movement of K+ into the mitochondrial compartments will disrupt proton movement into the intermembrane space. C. increase, because the net positive charge in the mitochondria will cause increased movement of protons into the intermembrane space. D. increase, because the additional positive charge will further activate ATP synthetase
decrease, because movement of K+ into the mitochondrial compartments will disrupt proton movement into the intermembrane space. Any disruption of the mitochondria will likely decrease ATP production. An influx of another positively charged ion into the compartment would disrupt the electrochemical gradient responsible for the necessary flow of protons.
after nucleus undergoes fission one frag moves away from the other it has
decreasing acceleration as the distance increases electrostatic force decreases so acceleration decreases
pressure = (both eqs)
force/area or dhg
at terminal velocity __ and __ are equal magnitude
forces of gravity and air resistance
explain protein hormones
form most hormones
solid solvent and gaseous or solid solute or a gaseous mix with gaseous can all be
formed to solutions
How are steroid hormones synthesized?
from cholesterol, which is a modified version of a TERPENE
reduction
gain of electrons decrease oxidation state
People who are born without sweat glands are likely to die of heat stroke in the tropics. This indicated that, under tropical conditions, the human body may: A. gain, rather than lose, heat by evaporation B. gain, rather than lose, heat by radiation C. need to use different mechanisms than in the temperature zones to maintain body temperature D. be better able to regulate body temperature than under temperature conditions
gain, rather than lose, heat by radiation If people lack sweat glands, they are unable to make sweat nor capitalize upon the evaporative cooling of sweat. These individuals nearly solely rely on vasodilation (radiation) for responding to elevated external temperature. This indicates that radiation alone is ineffective for cooling under these conditions. In fact, the human body may gain heat by absorbing radiation from the sun leading to an elevation in body temperature.
what is the difference between a galvanic/voltaic and electrolytic cell?
galvanic: uses spontaneous REDOX to produce current electrolytic: uses CURRENT to drive non-spont redox rxns
Roger's concept of incongruence
gap between ideal self & actual self
deposition
gas to a solid
what is the original cell called at the beginning of meiosis when it has two copies of the one parents dna
germ cells
Amphoteric meaning
give example + a substance that can act as both an acid and a base - eg: AA
Where is filtrate formed
glomerulus, not loop of henle formed as fluid passes from the glomerular capillaries through the glomerular membrane into Bowman's capsule
PEPCK is activated by
glucagon and cortisol
glycogen vs glucagon **do later
glucagon: released when insulin is too low glycogen: a form of carb
sucrose names
glucopyranosyl fructo furanoside fructo furanosyl glucopyranoside
Thermodynamic stability is determined by:
heats of combustion
What is the n+1 rule? when does it apply?
helps us determine how many peaks we would expect, only applies if the H is being split by one neighbour
low resistance ____ current
high
What primers are most suitable for PCR?
high GC content
Aromatic rings
highly conductive
Electronegativity
how close the atom pulls the covalent bond closer to them ex in H-F there is a large polar dipole towards F
name the 5 types of teeth
how many of each + function + - central incisors (4): cutting - lateral incisors (4): cutting - canines (4): gripping - premolars (8): grinding - molars (12): grinding
humanistic perspective
how to best apply to free will
predictive validity
how well a test score predicts future performance
Wavelength differences are perceived as differences in _____
hue
Selye's general adaptation syndrome
human's responses to various stressors are similar
energy =
hv h: plancks constant v: frequency
operant conditioning
if not reinforced preferred behavior goes extinct
myopic
imageforms infront of retina (nearsightedness
Mead's Theory
imitation stage, play stage, game stage
where is renal water reabsorption regulated????
in the COLLECTING DUCT
"out-group" meaning in sociology
in-group + a social group to which individuals do not believe they belong; its members are perceived as different and may be discriminated against or excluded in-group: individuals BELONG
Kidney failure during severs dehydration is most likely due to: A. inadequate blood volume for effective filtration B. inability to produce sufficient urine C. buildup of salts in the distal tubules D. increased body temperature
inadequate blood volume for effective filtration Severe dehydration greatly reduces the volume of filtrate moving through the nephrons of the kidney. If fluid volume is too drastically reduced, the kidney will be unable to effectively do its job of filtering and maintaining homeostasis.
in a series circuit with 2 resistors removing the second resistor would do what to the current drawn from the battery
increase it
purpose of villi and microvilli
increase surface area for absorption
If heroin dependent rats were injected with naloxone, this would have what effect on the reinforcing effects of heroin?
increase the reinforcing effects
in a series circuit with 2 resistors removing the second resistor would do what to the voltage drop and current through the first resistor
increase them both
What happens to the GFR when you: -increase afferent diameter: - increase efferent: - decrease afferent: - decrease efferent:
increase, decrease, decrease, increase
What is the effect of constriction of the efferent arteriole on the GFR and Na+ excretion?
increased GFR .˙. increased Na+ excretion
increase co2 exhale
increases blood PH
what is the difference between intracellular and intercellular?
intracellular: inside cell intercellular: between cells
Maois increase intraneuronal or extraneuronal epinephrine concentration?
intraneuronal b/c it prevents breakdown after reuptake is completed
electric potential energy r is related by an
inverse
What does the velocity of ions traveling through a uniform electric field depend on
ion mass-to-charge ratio
What gets reabsorbed in the ascending loop of Henle
ions only (actively), its impermeable to water
what is reaction rate (V)? write reaction rate (rate law) for A ----> B
is the amount of product formed per unit time (mol/sec) rate = K [A]
Tautomerization
is the process of converting one tautomer to another
how does chemical shift change with different spectrometers?
it doesn't! chemical shift is a constant no matter what spectrometer type you're using
where is atp synthase and what does it do
it spans the whole mitochondrial membrane and it is the gatekeeper in making ATP
pancreas
its hormones + - not as much involved with the pituitary gland as other glands - responsible for controlling blood sugar levels - hormones: insulin + glucagon
How do you know if an amino acid is involved in binding
its mutation must change the kd of the overall enzyme
Measure of catalysis rate
kcat
in a normal molecule, which is more stable, the ketone form or the enol form?
keto form
Anomie
lack of social norms --> breakdown in connection between individual & community
Starting materials of gluconeogenesis
lactate, oxaloacetate, alpha ketoglutarate
which part of the GI tract is responsible for constipation and diarrhea?
large intestine/colon bc its responsible for water absorption
7 types of intelligience
linguistic, logical, musical, visual, kinesthetic, interpersonal, intrapersonal
Glycoside bond
links monosacc in oligosacc (acetal linkage)
Membrane symport
lipophilic with polar and nonpolar groups
bile pathway
liver ===> common hepatic duct ===> cystic duct ===> stored in gallbladder ===> common bile duct ===> secreted into duodenum ===> ileum (where absorption takes place)
Hepatocytes
liver cells that maintain glucose levels in response to pancreatic hormone stimulation
Na is reabsorbed through the filtrate moving through the Nephron in the
loop of henley which is ultimately the mechanism whereby the kidneys concentrate urine
alpha decay means
losing an apha particle which is 2 protons and 2 neutrons
1st to be detected in chromatography is the
lowest affinity
if molecule x has a higher Ksp than molecule y, what does that mean?
molecule x will have a GREATER molar solubility/ more of it will DISSOLVE than molecule y
A ray of light in air is incident upon a glass plate at and angle of 45. The angle of refraction of the ray in the glass in 30. What is the index of refraction?
n1sinθ1 = n2sinθ2 n2 = (1 x sin45)/sin 30 = 1.41
ATP hydrolysis
needed for reactions that are non-spontaneous (+ G)
the inflation of the lungs in mammals is accomplished by
negative pressure pumping action because the lung stays in contact with the thoracic wall as it enlarges due to contraction of the diaphragm and the external intercostals
electrons come from the ---- side of the battery
negative!
beta particles have ___ charge so they are ____ by magnetic field gamma are ___ charged so they are ____ by magnetic field
negative, deflected not, aren't deflected
Is the liver involved in blood pressure regulation
no
amino acids net charge
no net charge
Adding a third parallel capacitor in a parallel circuit will do what to the voltage drop across capacitor 1 and charge stored on it
nothing
in a parallell circuit with two resistors removing resistor two would do what to the voltage drop of the first resistor and the current through the first resistor
nothing
once saturated increase in substrate does what to reaction rate
nothing
removing capacitor 2 from a parallel circuit with 2 capacitors does what to the voltage drop across capacitor 1 and the charge stored on it
nothing
in a parallell circuit with two resistors adding a third parallel resistor would do what to the voltage drop and current through the first resistor
nothing would happen to voltage drop and current
stereotype lift
occurs when awareness of positive expectations improve task performance
self-reporting bias
occurs when subjects skew their responses often to impress/appease researchers
when can a displacement rxn take place?
only if the metal/non-metal is MORE reactive than the one already in the rxn, then it can displace it
Osmotic vs hydrostatic Pressure
osmotic = done by plasma proteins, water goes IN capillary hydrostatic = water pushing against capillary wall, water LEAVES capillary
sound travels fastest in a solid
ossicles are solid stapes are reduced in size so depolarization is magnitized
fndamental attribution error
over value dispositional or personality based causes of behavior and under value external
which side of a concentration cell undergoes oxidation? reduction?
oxidation = less concentrated side / reduction = more concentrated side
Indicator does NOT affect _____
pH
pKa vs pH
pKA should be close to 1 unit of pH
R =
pL/A
hardy weinberg equilibrium
p^2 + 2pq + q^2 = 1 p + q=1
primase
part of replication
runaway selection
particular trait that has no effect on survival becomes exaggerated over time
Initial filtration in the glomerulus of the kidney occurs by
passive diffusion by countercurrent exchange system
functional fixedness
perceive an item only in terms of its most common use
Psychophysical discrimination technique
perception of stimuli in relation to true physical properties
what is a membrane protein that only exists on the surface called?
peripheral proteins
capacitance =
permivity of free space * (Area of the plates / distance between plates)
Gamma decay occurs when a nucleus emits a
photon
semi circular canal
pitch intensity and dizziness
Function of phospholipids depends on:
polar head & degree of saturation
what does chirality refer to?
polarized optical activity
Most bacterial cells and human cells are alike in: A. the ability to produce ATP via ATP synthase B. the chemical composition of their ribosomes C. their enclosure within cell walls D. the shape of the self-replicating structures that carry their DNA
the ability to produce ATP via ATP synthase Both types of cells possess a membrane-embedded ETC capable of generating a H+ gradient, which drives ATP synthesis via ATP synthase. This ATP synthesis takes place on the plasma membrane of bacteria and on the inner mitochondrial membrane in human cells. The chemical composition of eukaryotic and prokaryotic ribosomes are similar, but are distinct enough that several types of antibiotics are able to preferentially target prokaryotic ribosomes over eukaryotic ribosomes.
primary structure of basic protein is formed when
the amino acid terminus of one amino acid attacks the carboxy terminus of another
What is hydrolysis?
the chemical breakdown of a compound due to reaction with water using enzymes in the mouth
If oligonucleotides such as mRNA were not degraded rapidly by intracellular agents, which of the following processes would be most affected? A. the production of tRNA in the nucleus B. the coordination of cell differentiation during development C. the diffusion of respiratory gases across the cell membrane D. the replication of DNA in the nucleus
the coordination of cell differentiation during development The destruction of mRNA prevents continuous protein production, allowing the cell to change its protein expression over time. The coordination of cell differentiation during development is very sensitive to the timing of mRNA turnover, while the other responses are not affected as much by the timing of mRNA turnover
difference between upper and lower esophageal sphincters?
the upper is under SKELETAL control while the lower one is involuntary
in oxidative phosphorilization the energy needed to create ATP comes from which favorable reaction
the correct answer is hydrogen moves from the inter membrane space into the mitochondrial matrix
What sociological cocnept discuess the knowledge, skills, and education required for practicing medicine
the cultural capital of physicians
construct validity
the degree to which a test measures what it claims, or purports, to be measuring
concurrent validity
the degree to which the measures gathered from one tool agree with the measures gathered from other assessment techniques
sign-conserving synapse
the depolarization of the pre-synaptic cell causes the depolarization in the post-synaptic cell
what is responsible for the concentration of urine before excretion
the distal tubule and the collecting duct
central nervous system derived from
the ectoderm
when asked about lewis structures of NO or any other kind
the electrons add up to 11 so count out 11 electrons in the bonds and not shared ones
electron affinity
the energy associated with the ADDITION of an electron + EA: energy is required to add electron - EA: energy is released to add electron
Protease
the enzyme that breaks down proteins into smaller parts
what is a use for the base-promoted saponification/hydrolysis rxn?
the first step in breaking down triglycerols
Muscles with striated fibers are the primary muscle type in: A. the heart B. the uterus C. arteries and veins D. the small intestine
the heart Skeletal and cardiac muscle contain striated muscle fibers, smooth muscles do not the heart - is cardiac muscle, striated uterus, arteries and veins, and the small intestine are smooth muscle
experimenter bias
the influence of the experimenter's expectations on the outcome of research
"solvation shell" =
the layer of solvent in the environment surrounding a protein eg: water coating ball
blood and the arteries and parasites are derived from
the mesoderm
higher vapor pressure means
the molecules react better with solvent-solvent, or solute-solute, not solvent-solute so they EVAPORATE QUICKER especially if they are not alike
saponification
the opposite of esterification, where as esterification is ester condensation, saponification is ester hydrolysis - can either be base or acid promoted
vapor pressure
the pressure exerted by a vapor over a liquid
Peristalsis
the process of wave-like muscle contractions of the esophagus that moves food along
What will happen if a homogenous catalyst can't be separated from the products at the end of a reaction?
the products will be contaminated
allosteric control/regulation
the regulation of a protein by binding an effector molecule at a site other than the enzymes active site. the effector binds to the site called the allosteric site.
3 parallels in a circuit if one is blocked then if another is blocked will do what to resistance
the resistance will increase with the first taken away and increase even more than the first time with the second one taken away
solute
the solid dissolving solvent is the water or whatever
ecological validity
the study represents what happens in real life
how does blood contain DNA if RBCs don't have nuclei??
recall that blood doesn't just contain RBCs but other blood cells like leukocytes (which do have nuclei)!!
context effect
recalling similar things successfuly
false alarm
recalling things that weren't there
LAH
reducing agent that disrupts disulfide bridge (tertiary structure)
what are the 2 uncatalyzed movements in the cell membrane?
1- transbilayer diffusion: when the phospholipids on the inner and outer leaflets FLIP-FLOP (slow) 2- lateral diffusion: no switching between leaflets, but switching within the same leaflet (fast)
parietal cells
- found in stomach - secrete HCl
Glial cells
-Astrocytes: nourish, form BBB (CNS) -Microglia: phagocytic, break down (CNS) -Olgi/schwann cells (PNS) --> Myelin -Ependymal: line ventricle & produce CBS
S2 vs O2
-Both have same # of valence e-, & produce NO dipole moment - S2 has a ↑ atomic radius, larger e- cloud, & double bond is longer
Glycolysis
-Glucose --> 2 pyruvate -Preparatory phase: 2 ATP -Payoff phase: 4 ATP -Produce: 2 NADH, 2 ATP -Irreversible: ALL kinase & PFK-1 -Reversible: PFK-2, G,3-PD, 3-PGK -Rate-limiting: PFK-1 (indirectly stimulated by insulin) -1,3BPG: production of ATP (substrate phos), NADH, & ensures efficient O2 release in RBC -DHAP (prod by F1,6-BP): converted to triacylglycerol synthesis in hepatic & adipose tissue -PEP: produces ATP
Glucose transporters
-Glut 2: liver, pancreatic B-cells, ↑ Km, unsat -Glut 4: adipose/muscle, insulin, ↓ Km, sat
3 parts of small intestine
1. Duodenum 2. Jejunum 3. Ileum
bile pathway (steps)
1. Liver produces bile and it flows through the hepatic ducts into gallbladder. 2. fat stimulates CCK release 3. gallbladder contracts and releases bile into the common bile duct, which drains into the duodenum 4. the bile, originally produced in the liver, emulsifies fats in partly digested food, thereby assisting their absorption.
Which of the following best describes cell signaling in which the same cell both emits and receives a signaling molecule? A) Juxtacrine B) Autocrine C) Paracrine D) Endocrine
B) Autocrine Autocrine signaling acts on the same cell (choice B is correct). Juxtacrine signaling acts on the adjacent cell (choice A is incorrect). Paracrine signaling acts on cells in the same area that are not necessarily adjacent (choice C is incorrect). Endocrine signaling functions through hormones that travel through the bloodstream to their target tissues to exert their effect (choice D is incorrect).
Which of the following is NOT a site in the ribosome? A) E B) A C) G D) P
C) G G is not a site in the ribosome (choice C is correct). The A, P, and E sites are where the incoming tRNA binds, the transferase reaction occurs, and the tRNA exits, respectively.
Which of the following hormones does the pineal gland primarily secrete? A) Oxytocin B) Prolactin C) Melatonin D) Insulin
C) Melatonin The pineal gland primarily secretes melatonin, which is important for regulating circadian rhythms (choice C is correct). Oxytocin is released by the posterior pituitary (choice A is incorrect). Prolactin is released by the anterior pituitary (choice B is incorrect). Insulin is released by beta cells in the pancreas (choice D is incorrect).
Which of the following semicarbazones is the product of thermodynamic control? A. Cyclohexanone, because the more stable product forms faster B. Cyclohexanone, because it contains more alkyl substituents to a double bond than does the other product C. 2-furaldehyde, because it is produced under equilibrium condition and is more stable than the other product D. 2-furaldehyde, because its potential energy is higher
C. the thermodynamically controlled product is the one that is formed under equilibrium conditions and is more stable.
If the breathing rate is 10 breaths/min, the tidal volume is 800mL/breath, and the dead space is 150 mL, what is the net volume of fresh air that can enter the alveoli each minute? A. 650 mL B. 785 mL C. 6,500 mL D. 7,850 mL
C. tidal vol is amount of air that moves into lungs during each inspiration, dead space is amount of air that doesn't reach the alveoli, 800-150 = 650 mL/breath x 10 breaths/min = 6,500 mL
Which of the following molecular interactions plays the biggest role in protein secondary structure? A) Van der Waals B) Hydrophobic interactions C) Salt bridges D) Hydrogen bonds
D) Hydrogen bonds Hydrogen bonding plays the biggest role in secondary structure, which includes alpha helices and beta sheets. In secondary structure, hydrogen bonding allows bonds to form between backbone carbonyl oxygens and nitrogens, which lead to the observed secondary structures. Choices A-C all play a role in tertiary and quaternary structure.
Which of the following lobes of the brain is primarily responsible for visual processing? A) Frontal B) Temporal C) Parietal D) Occipital
D) Occipital The occipital lobe is primarily responsible for processing visual information (choice D is correct). The frontal lobe is involved in higher-level thinking and reasoning (choice A is incorrect). The temporal lobe is involved in sound processing and speech (choice B is incorrect). The parietal lobe is involved in processing sensory information (choice C is incorrect).
Relationship between Resistivity and Temperature
Directly proportional
equation linking standard cell potential and k (using log)
E˚ = (0.0592V/n) * log k -v is for volts not volume-
Glucose typically enters the cell through which mechanism? A. Simple diffusion through the cell membrane B. Facilitated diffusion through a carrier protein C. Pinocytosis through a channel protein D. Active transport by a glucose transport protein
Facilitated diffusion through a carrier protein Glucose is too large and polar to move quickly through the cell membrane by simple diffusion. Typically the concentration of glucose outside the cell is higher than inside the cell. Since glucose is moving down a concentration gradient by entering the cell, the process does not require ATP. Glucose typically enters cells by facilitated diffusion through a carrier protein.
glycogenolysis and gluconeogenesis
Glycogenolysis: promoted by thyroxine (sugar absorbance). Uses glycogen Gluconeogenesis: promoted by epinephrine (fatty acid release) & cortisol (carb metabolism)
Glycosphingolipid vs Ganglioside
Glycosphingolipid: cerebroside & globoside Ganglioside: oligosacc & NANA
List of anterior pituitary hormones
Growth hormone (GH) Thyroid-stimulating hormone (TSH) or thyrotropin Adrenocorticotropic hormone (ACTH) Follicle-stimulating hormone (FSH) Luteinizing hormone (LH) Prolactin (PRL)
Hunds rule vs n + 1 rule
Hund's: orbitals n + 1 : energy level/subshell
V (drop at R)= (voltage)
I(through resistor)R(of resistor)
Capital
Intellectual: knowledge Social: network of individuals Cultural: charac, skills, educations due to social status Human: intrinsic ability to perform tasks
Types of mobility
Intragenerational: moving from one social class to another Intergenerational: change in social position relative to your generation
Reactivity of a metal depends on its
Ionization potential
Catalytic Efficiency
Kcat/Km
when concentration of Cr = x and OH = 3x what is the Ksp formula
Ksp = (x)(3x)^3 = 27(x)^4 plug in molar solubility for x
what enantiomer of amino acids makes up ALL of the aa in the human body?
L-AA
What amino acids have additional amino groups?
LYS & ARG
When the environmental temperature is 45C, which of the following organisms will have the highest body temperature? A. Human B. Kangaroo rat C. Lizard D. Camel
Lizard Kangaroo rats and Camels have great cooling mechanisms. Humans have some cooling mechanisms, while lizards have the worst cooling mechanisms because they can't sweat and can''t do vasodilation.
Increased vasoconstriction has an important role in which of the following situations? A. Causing the decrease in blood pressure associated with fainting B. Increasing blood flow to muscle during exercise C. Increasing blood flow to skin during blushing D. Maintaining blood pressure during a hemorrhage
Maintaining blood pressure during a hemorrhage As blood is lost from the circulation, reduction in vessel size helps maintain the necessary pressure to keep the blood circulating to all body tissues. Vasoconstriction, the narrowing or a vessel, restricts blood flow to an organ and can increase blood pressure, whereas vasodilation has the opposite effect. Vasodilation increases blood flow to both the muscle during exercise and the skin during blushing.
Path of proteins undergoing retrograde transport?
PM --> Golgi --> ER
paramagnetic vs diamagentic
Para: unpaired e-, align, attracted Dia: paired e-, unalign, repelled
Reduced permeability of potassium leak channels would affect which of the following aspects of action potentials in a neuron? The activation threshold The time to reach maximum repolarization The time to reach maximum depolarization The size of the depolarization wave
Potassium leak channels allow potassium to exit a neuron in response to depolarization. Reduced permeability of a leak channel to its natural ion means that the rate the ions are able to cross the channel is reduced. Reduced permeability of potassium leak channels would affect the time to reach maximum repolarization in a neuron.
primary vs secondary active transport
Primary - transport directly coupled with ATP Secondary- one molecule goes with its gradient, the other against the gradient (symport vs. antiport)
Mutations in receptor tyrosine kinases would most likely be associated with: Endocrine diseases Neurologic diseases Cancers Metabolic abnormalities
RTKs are often associated with growth factors. Mutations in specific RTKs may cause uncontrolled growth, leading to cancers.
Energy consumed over time in a pipe subject to boiler scale
Radius decreases and Pressure inversely proportional to r^4, energy (work) is proportional to pressure difference, so energy increases exponentially with time
Spermatogenesis
S phase: Primary sperm Meiosis I: Secondary sperm Meiosis II: Spermatid Maturation: Spermatozoa
What gets reabsorbed in the PCT?
SODIUM, glucose, AA, water
What keeps the penis flaccid when a male is not sexually aroused?
SYMPATHETIC nervous system - norepinephrine vasoconstricts the blood vessels
One specific type of antidepressant medication works by blocking the removal of neurotransmitters. Which of the following neurotransmitters is most likely the target of the antidepressant medication? Serotonin Acetylcholine GABA Dopamine
The neurotransmitter must be classified as one of the types that is associated with attention, cognition, and emotion. The medication works by blocking the removal of the neurotransmitter; acetylcholine is not removed from the receptor, but is broken down by enzymes. Selective Serotonin Reuptake Inhibitors (SSRI's) function by blocking the reuptake of serotonin, which allows more serotonin to be present.
electron configuration of Zn electron configuration of Zn^2+
[Ar]4s^2,3d^10 ions you subtract the electrons from the s orbital first so it would be [Ar]3d^10
if torque = 0 than
acc = 0
Gabriel synthesis is
an R group with a halide that uses the halide to connect the R group with an N that's part of a 5 member ring and then breaks off to form NH2 connected to R; THIS REACTION DOES NOT USE NH3
foraging behavior
animal letting predator know it doesn't have the element of surprise
Transition state analogs act as
antagonists
overextension
applying a word to a wider collection of objects and events (ex. saying dog when u see a cow)
Prokaryotes replicate via _____
binary fission
when one prokaryote replicates it does so viea
binary fission where the new copy of the dan is attached to the cell
when does a primary oocyte undergo finish meiosis 1?
at puberty /13 yo or so
A person on a sled is moving to the right along a horizontal frictionless surface. The person throws a ball straight upward, why does their velocity not change?
because of Newton's 3rd law; when the person throws the ball upwards, the person is exerting force on it .˙. the ball exerts the same force back on the person
There is a 1-liter container filled with 500 milliliters of water placed on top of a scale displaying 80 pounds. When a metal cube is submerged in the water, will the scale read >80, =80, <80?
because the object is floating, it has a buoyant force upwards aka water pushing on object and .˙. newton's 3rd law = object pushes on water with a force (Fg AKA weight) .˙. scale will be more than 80
Ca2+ does what
binds to troponin complex
"filtrate" =
blood that enters bowman's capsule to get filtered
Adding a third parallel capacitor in a parallel circuit will do what to the total capacitance and charge drawn from the battery
both go up
surfactant
both phospholipids and proteins can contribute to its hydrophobic properties proteins are mostly hydrophilic but have some hydrophobic r groups
random culling of a gene pool due to a natural disaster or overhunting
bottleneck effect
purpose of pepsin in the stomach
breaks down PROTEINS in the stomach
"hepatic lobules" =
contain hepatic (liver) cells
delta G =
delta H - T(delta S)
several weeks of starvation acetyl CoA is primarily converted into keynote bodies
gluconeogenesis depletes the supply of oxaloacetate which is essential for the entry of acetyl Co A into the Krebs CyCle
negatively charged amino acids
glutamic acid and aspartic acid
triglyceride structure
glycerol + 3 fatty acids
all triglycerides but not all phospholipids have a ______
glycerol backbone
What pathways are upregulated during the transition from intrauterine to extrauterine environment?
glycogenolysis followed by gluconeogenesis
anaerobic respiration occurs after
glycolysis
what process drives the cleavage of a peptide bond?
hydrolysis
what type of reaction is a saponification?
hydrolysis, neutrophilic addition
The environment of the retinal binding site is
hydrophobic
REM rebound
increased REM sleep caused by REM-sleep deprivation.
what does fMRI measure
increased blood flow (NOT INCREASED BLOOD GLUCOSE LEVELS)
While diving, when your heart rate and breathing rate are increase, you notice that you are producing more urine. Why? A. increased blood pressure caused by excitement or anxiety B. reduced blood pressure caused by excitement or anxiety C. absorption of water from the ocean D. inability to cool the skin through evaporative water loss
increased blood pressure caused by excitement or anxiety increased urine production can be explained by an an increased blood pressure caused by adrenaline, released in response to excitement or anxiety - the flight or fight response
in a fed state, fatty acid synthesis would be_______and β-oxidation would be ______
increased, decreased
higher temp does what to the ph
increases the Kw which lowers the ph and the pOH
what is the ONLY way we can change K (equilibrium constant)?
increasing/decreasing the TEMPERATURE
if the air pressure goes down
increse in breathing air increase in tidal volume increase in secretion of erythropoitin
Ksp
indicates solubility of ionic compound in water K constants are temp dependent also pressure dependent for dissolved gases
Deindividuation
individual loses them self in group's identity
social loafing
individuals become less productive in groups
Cognitive Appraisal Theory
individuals decide on an appropriate emotion following the event
An intravenous infusion causes a sharp rise in the serum level of albumin (the major osmoregulatory protein in the blood). This will most likely cause an: A. increase in the immune response B. influx of tissue fluid to the bloodstream C. outflow of blood fluid to the tissues D. increase in tissue albumin levels
influx of tissue fluid to the bloodstream Albumin is one of the major plasma proteins. Plasma proteins can't cross the walls of the blood vessels, but water molecules can. The wall of the artery acts as a semipermeable membrane setting up the conditions needed for osmosis to occur. An increase in the plasma albumin will upset the osmotic balance because the blood will become hypertonic with respect to the tissue. Water will have to flow into the blood stream to reestablish equilibrium. So an increase in the plasma protein would cause fluid to enter the bloodstream
another name for tongue
longula
dissociative disorder
loss of memory
The most effective method for producing an increase in the total amount of water lost through the skin during a certain period would be: A. inhibiting kidney function B. decreasing salt consumption C. raising the environmental temperature D. increasing water consumption
raising the environmental temperature This would cause a person to perspire, releasing water to the environment where it can evaporate and cool the body.
what releases Ca 2+ in muscle contraction
sarco reticulum
pyranoses have_______
six member rings glucose mannose galactose
which of the following will effect the intensity of the wave experienced by the detector measuring the sound wave
surface area of detector and distance from source to detector
path of sperm
testes ===> epididymis ===> vas deferens ===> urethra
what is a "reduction potential"?
the E˚ value associated with the half-reaction of a substance getting reduced. eg: x^+ + e^- = x (s) E˚ (V) = +0.8
What 4 enzymes are secreted by the exocrine pancreas?
their function + 1. Secrete bicarbonate to neutralize stomach acid 2. Secretes amylase (which breaks down starch) 3. Lipase; breaks down lipids 4. Proteolytic enzymes (inactive version): trypsinogen + chymotrypsinogen
opinioin <- give them something to read from different opinions
their opinions strengthen
Why would an amino acid commonly found in the body not be found in proteins synthesized in vivo?
there is no codon for it in the genetic code
how do hormones produced by the hypothalamus and designated to the pituitary gland get there?
they DIRECTLY travel down nerve axons from the hypothalamus to the anterior pituitary .˙. it gets DIRECTLY taken up by the pituitary gland WITHOUT HAVING TO CIRCULATE AROUND THE REST OF THE BODY FIRST
In comparison with the wall of the right ventricle of the heart, the left ventricular wall is: A. thinner and generates a higher pressure when it contracts B. thinner and generates a lower pressure when it contracts C. thicker and generates a higher pressure when it contracts D. thicker and generates a lower pressure when it contracts
thicker and generates a higher pressure when it contracts The right ventricle pumps blood through the lungs, the left ventricle pumps blood through the entire body.
If a person's gallbladder is removed, the person should restrict the consumption of: A. proteins B. triglycerides C. polysaccharides D. lactose
triglycerides The gallbladder stores bile produced by the lover. The major dissolved components of bile are breakdown products of hemoglobin such as bilirubin and bile salts. Bile salts are amphipathic. Since triglycerides are hydrophobic fats, bile would aid in their digestion.
tropic vs direct hormones meaning
tropic: hormones that stimulate other glands to release their hormones direct: act DIRECTLY on target organ
troponin complex allows
tropomyosin to expose myosin binding site in action
korsakoff syndrome
trouble learning new info they don't lie they have bad memory
what activates chymotrypsinogen
trypsinogen? + enteropeptidase
vas deferens
tube that carries sperm from the epididymis to the urethra
tertiary structure
what type of bonds + Irregular contortions of a protein molecule due to interactions of side chains involved in HYDROPHOBIC interactions, ionic bonds, hydrogen bonds, and disulfide bridges.
What is dimagnetism?
when the induced electron magnetic field goes in the opposite direction to the external magnetic field
selection bias
when the sample is not representative of the population
when does a secondary oocyte undergo meiosis 2?
when the sperm fuses with the egg =====> becomes OVUM then a zygote
juxtaglomerular apparatus
where the distant convoluted tubule kisses the glomerulus and regulates BP
Area under a PV curve represents
work done
What is the ΔS of the following reaction? 2O3 --> 3O2 S O3: 238.8 S O2: 205.0
ΔS rxn = ΔS products - ΔS reactants ΔS rxn = 3(205) - 2(238.8) = 137.4
Electrical potential energy
↑ : 2 like charges move closer ↓ : 2 opp charges move closer -amount of work req to bring + charge to Efield
What does fluidity depend on?
↑ Unsaturation & length of tails (longer = ↑ fluid)
Demographic transition occur due to:
↑ access to healthcare & ↓ birth rates
When is ANP released?
↑ blood pressure
PCR
↑ copies of DNA -Dideoxynucleotides : terminate replication. -Deoxynucleotides : continue replication.
selective recall
↑ likelihood of remembering favorable info
Gibbs free energy equation - electrochemistry
∆G = -nFE
which of these can change with changing concentration (and how/why)? Keq, ΔG°', ΔG, the rate constant k
∆G only! the rest are constants/don't change with changing of conc. bc of this relationship: ΔG= ΔG˙ +RT lnQ
∆G =
∆H - T∆S
Moral Reasoning (Kohlberg)
-Pre-conventional : consequences (reward/punish) -Conventional: r.s to others (social norms) -Post-conventional: higher level reasoning (ethics/rights)
Is denaturation of proteins cooperative or non-cooperative?
Cooperative
Types of mirrors
-Concave: converge, r (+), f (-), real-inverted (distance > focal) & virtual-upright (distance < focal) -Convex: diverge, r (-), f (+), virtual-upright
Phenol
-Conjugate base has more resonance structures & negative charge of O- is delocalized over benzene ring -Aromatic, acidic
Types of motion
-Linear: free fall, velocity/acceleration are parallel or anti -Projectile: Neglig air resistance, gravity force -Circ/uniform: Centripetal force (inward), U (constant), no work
Plots
-NMR: detect structure/func group -IR: detect double/triple bonds (vibration must change dipole). O-H (broad 3300), Carbox acid (sharp 3000), N-H (sharp 3300), C=0 (sharp 1750) -UV: detect conjugated alkenes
Hormones
-Peptide: extracell, 2nd messenger, rapid, short-lived, no carrier -Steroid: intracell, conform change, slow, long-lived, carrier -Amino acid: Epinephrine, Norepinephrine, Thyroxine
Protein structure
-Primary -Secondary: alpha-helix & B-pleated (H-bond between backbone amide protons & carbonyl oxygens) -Tertiary: Disulfide bond, H-bond, Salt bridge, hydrophobic interactions, protein misfolding -Quaternary
Fermentation
-Pyruvate --> NAD+ (anaerobic ONLY) -Animal cells: Pyruvate -Human cells: Ethanol & CO2
Potentiometric titration
-Redox titration using voltmeter (no indicator). -measures emf
male reproductive system
-Seminiferous tubules: sperm (Sertoli cells) -Interstitial cells of Leydig: testosterone/androgens -Epididymis: sperm maturation -Vas deferens: ↑/↓ testes & connect epididymis to duct -Seminal vesicles: alkaline fructose -Cowper's gland: lubricant, urine
Types of memory
-Sensory: lasts for seconds & includes Iconic memory (recall specific details) -Short term -Long term: recall, rehearsal, ↑ neural connections (explicit & implicit memory)
Types of pathways
-Visual: Retina -> Nerve -> Chiasm -> LGN -> Radiations -> Cortex -Auditory: Cochlea -> Vestibulocochlear Nerve -> MGN -> Cortex -Olfactory: nerve -> bulb -> tract -> limbic system
Liver
-metabolic powerhouse -drug detox, bile prod, glucose reg, cholesterol metab
Explain steroid hormones
-they come from lipids (mostly cholesterol) - bc they're lipid soluble, their receptors are located inside the cell .˙. primary messenger - they affect transcription and translation
how are things ABSORBED in the jejunum?
1) AA + nucleotides: primary active transport 2) carbs: secondary active transport 3) fats: b/c they're lipids, they just diffuse into membrane, get rearranged into chylomicrons, and absorbed into lymphatic capillaries
what are the 4 problems with the traditional central dogma theory?
1- info can flow backwards from RNA to DNA using the enzyme REVERSE TRANSCRIPTASE 2- ncRNA: non-coding RNA that doesn't get translated to protein but works directly as RNA 3- epigenetics: a change in phenotype w/o a change in genotype - i.e. change in gene EXPRESSION such as methylation and histone modifications 4- RNA viruses could have their RNA be used as template to create more RNA
what 2 things is testosterone converted to?
1-DHT (99%) 2- estrogen (<1%)
A carboxylic acid is found to be mostly deprotonated at a pH of 3.3. Which of the following could be its pKa? A. 2.8 B. 3.4 C. 4.2 D. 6.7
A. A protic group will be mostly deprotonated when the pH is greater than the pKa (the half-equivalence point). The only way most of the acid could be deprotonated at a pH of 3.3 is if the pKa is lower than that, making (A) the only possible answer.
A student measures the temperature of a system as energy is added to it. The temperature rises linearly and over time begins to level off before reaching a plateau. The student notes that energy continues to be added at a constant rate. Which of the following conclusions must be true based on this information? A. The system is not closed, and loses energy to its surroundings. B. The system is undergoing a phase change and thus it plateus. C. The electrons of the system have reached their maximum energy state and cannot be excited any further. D. The scenario is not possible and the student has made a measurement error.
A. The gradual leveling off and plateauing of the temperature is consistent with an open system emitting energy at an increasing rate as the amount of energy it contains rises. Eventually, the rate of energy emission will equal energy input and the temperature will cease to rise. (B) is incorrect because a phase change would result in an abrupt plateau and then a continuation of temperature rise after the phase change; this isn't being described. (C) is incorrect because temperature is not dependent on electronic energy state. (D) is incorrect because indeed this scenario is possible as the prompt never indicates that the system is closed.
Visible light travels more slowly through an optically dense medium than through a vacum. A possible explanation for this could be that the light: A. is absorbed and re-emitted by the atomic structure of the optically dense medium B. is absorbed and re-emitted by the nucleus of the material in the optically dense medium C. bounces around randomly inside of the optically dense medium before emerging D. loses amplitude as it pass through the optically dense medium
A. A is known to occur and is the reason for the slowing down of light. The atomic structure of the medium re-emits light, not the nucleus. C is incorrect because the motion of the photons is certainly not random
Which of the following is most likely to decrease the forward rate of reaction for the following reaction? A
B -> C + D A) Increasing the concentration of reactant A B) Decreasing the concentration of reactant B C) Introducing a new chemical species D) Decreasing the concentration of product C + B) Decreasing the concentration of reactant B By Le Châtelier's principle, decreasing the concentration of reactant B will cause the backward rate of reaction to increase, or the forward rate of the reaction to slow down (choice B is correct). Increasing the concentration of reactant A or decreasing the concentration of product C would cause the forward rate of the reaction to increase (choices A and D are incorrect). It is difficult to predict how the introduction of a new chemical species would affect a reaction without knowledge of how the species acts (choice C is incorrect).
Which of the following does not correctly represent Power? A. P = I²R B. P = IR²/V C. P = IV D. P = V²/R
B. Recall P = IV [so we can eliminate (C)] and V = IR; I = V/R and R = V/I. If we substitute IR directly for V, we get P = I²R. (A) is incorrect. If we substitute V/R for I, we get P = V²/R, so (D) is incorrect. Thus (B) must be the correct answer; if we substitute IR for V in P = IR²/V, we get P = IR²/IR; P = R. This is false.
Which of the following is true as the membrane potential of a neuron crosses from negative to positive during depolarization in action potential? A. Sodium reverses its direction and begins to flow out of the cell. B. Sodium continues to flow into the cell until the voltage has reached a certain positive threshold. C. Potassium begins to flow out of the cell. D. The sodium-potassium pump ceases to function until the neuron has repolarized.
B. There is nothing particular special about the threshold of 0 mV during the action potential. The resting potential is approximately -70 mV and the action potential peaks at approximately +40 mV when the sodium channels begin to close and the potassium channels open. Thus, as the 0 mV barrier is crossed, sodium continues to flow into the cell making (B) the correct answer. (C) does not occur until the peak of the action potential has been reached; (D) does not occur as the pump operates independently of action potentials.
Which of the following cycloalkanes would be predicted to have the lowest reactivity? A. Cyclopropane B. Cyclohexane C. Cyclopentane D. Cyclobutane
B. This question asks for the molecule with lowest reactivity, or in other words, which molecule is the most stable. Stability increases as the number of carbons in the cycloalkane increases. Thus we know that cyclobutane is more stable than cyclopropane and cyclohexane is more stable than cyclobutane. This is due to decreased ring strain. An interesting phenomena is that beyond cyclohexane, there is a notable decrease in stability; this is largely due to the very large inherent stability of cyclohexane. It exists in such a geometry that it can maintain an almost perfect tetrahedral geometry. This is not seen in the cyclopentane or other larger cycloalkanes. Thus the answer to this question is (B), cyclohexane.
The gravitational force between planets X and Y is F. If both planets double in mass, and the distance between them triples, what is the force between them? A. 1/3 F B. 4/9 F C. 4/3 F D. 2/3 F
B. Using the equation F=Gm₁m₂/r², we see that if both masses double, then the force increases 4 times, but if the distance between them is tripled, then the force decreases 9 times, thus 4/9 F is the correct answer.
Which of the following is FALSE regarding DNA replication? A. DNA replication requires an RNA primer. B. Nucleoside triphosphates are added to the 3' end. C. Bacteria require telomerase to complete their DNA strand synthesis. D. Helicase is required prior to DNA synthesis.
C. Due to their nonlinear nature, bacterial chromosomes do not face the same issues as eukaryotic chromosomes during DNA replication. With linear eukaryotic chromosomes, the ends of chromosomes need consistent elongation in order to prevent the successive shortening of their ends. The enzyme telomerase addresses this issue by providing a template and enzyme to lengthen the linear end with each cycle of DNA replication.
The phosphodiester bond is found in which of the following? A. Carbohydrates B. Proteins C. Nucleic acids D. Lipids
C. Phosphodiester bonds link nucleotides in nucleic acids. Carbohydrates are linked by glycosidic bonds, and proteins linked by peptides. Lipids are generally not polymeric.
Certain neurons have been found to have almost negligible refractory periods. What physiological property could be expected of this neuron? A. Long time points between neuronal firing B. Having very few sodium channels C. Potassium channels with the ability to close very quickly D. Lacking myelination on axons
C. To solve this problem, you must think about what causes the refractory period. After an action potential, potassium channels open to allow potassium out of the cell in order to repolarize the neuron to basal potential. These channels close quite slowly, thus what actually occurs is too much potassium flows out and the potential is actually less than basal, i.e. the neuron becomes hyperpolarized. If potassium channels were capable of closing very quickly, such a refractory period would likely not occur because the hyperpolarization of the neuron would not be observed.
In order for a drug to be able to be excreted via the urine, the drug or its metabolites must: A. be ionic in nature. B. be peptide-based. C. traverse the membrane of the glomerulus. D. enter the urine separate from blood circulation.
C. Urine is produced by filtration of the blood, so excretion of wastes and metabolites through the urine will be through blood filtration, making (D) incorrect. The drug or its metabolites must be able to pass the membrane of the glomerulus which is the capillary bed where filtrate escapes the blood and is concentrated in the nephron. Ions poorly traverse the membrane, making (A) incorrect; moreover, nonionic compounds are capable of entering the urine. The same objection can remove (B) as well. This leaves (C) as the correct answer.
Which of the following is an example of lower motor neuron dysfunction? A. An individual sits in a relaxed position with her knee partially flexed. When her foot is pulled upward, the individual involuntarily and rhythmically moves her foot up and down. B. An individual is told to relax her body. Despite attempts to relax, she experiences repeated, uncontrollable muscle spasticity. C. An individual is told to lift her left arm, and she has difficulty doing so. Her left arm appears shriveled and shorter than her right arm. D. A metal object is dragged along the bottom of an individual's foot and her toes go into extension away from the bottom of her foot.
C. The extensor plantar response (or babinski reflex) is a sign of upper motor neuron dysfunction and can be seen when a noxious stimuli is placed on the bottom of the foot, causing the toes to go into extension away from the bottom of the foot, rather than flexing down in the direction of the bottom of the foot. The involuntary rhythmic contraction of antagonist muscles is known as clonus and is a sign of upper motor neuron dysfunction. Muscle spasticity is a feature of hypertonia, or increased tone of skeletal muscle, and is an upper motor neuron sign. Extreme weakness and shrunken muscle is an example of atrophy, which is a sign of lower motor neuron dysfunction.
Conservative vs Nonconservative forces
Conserv: path indep, conserve Emech, Gravity/elastic Nonconserv: path dep, Emech lost, Friction/Air resist/Viscous/convection
Based on Chargaff's rules, if a cell's DNA contains 23% thymidine nucleotides, what percentage of nucleotides are guanine? A) 23% B) 46% C) 15% D) 27%
D) 27% Chargaff's rules state that the amount of adenosine (A) and thymidine (T) are equal in a cell, and the amount of guanine (G) and cytosine (C) are also equal in a cell. So, if there is 23% T, there is also 23% A, which is a total of 46%. 100 - 46 = 54, so G and C must make up the remaining 54%. 54 divided by 2 is 27, so the cell contains 27% G and 27% C.
A strong base is titrated with a weak acid. Which of the following is the most likely equivalence point pH? A) 3 B) 4 C) 7 D) 9
D) 9 A strong base-weak acid titration will result in an equivalence point with a pH greater than 7 (choice D is correct; Choices A, B, and C are incorrect).
As bubbles break the surface of the water, a thin film often rises above them. Which of the following contribute to this formation? I. Adhesion II. Cohesion III. Buoyant force A. I only B. II only C. I and II only D. II and III only
D. The surface of water that forms above a bubble is a result of the upward force exerted by the bubble, thus buoyant force, as well as the surface tension of the water. Surface tension is a cohesive phenomenon. Adhesion, the tendency of fluids to interact with unlike surfaces, would result in an upward movement after the bubble has eclipsed the surface, rather than before, thus choice D, cohesion and buoyant force only, is correct.
AFter a block begins to slide once static friction is overcome, how does its speed vary with time? A. it was constant in time B. It increased exponentially with time C. it was first constant, then increased linearly with time D. it increased linearly with time
D. Coefficient of kinetic friction always lower than that of static friction. Therefore there is a net acceleration on block once it starts to slide thus velocity increases with time. Constant acceleration = increasing velocity. a = F/m
An effective and efficient method for the delivery of an antisense gene could be: A. orally as an emulsified product B. microinjection into individual body cells C. intravenously as a nonantigenic, blood-stable product D. infection of and embryo by a virus modified to carry the gene
D. For an antisense gene to work, it must be incorporated into the cell in which it will perform its jobs so that its product is available to hybridize with the sense mRNA that needs to be blocked.
The pancreas produces which of the following substances for the digestive system? A. bile salts B. emulsifier C. gastric juices D. proteolytic enzymes
D. the pancreas produces several proteolytic enzymes which are released into the small intestine where they are converted to their active forms
Von Gierke disease is an autosomal recessive disorder characterized by a deficiency in the enzyme Glucose-6-phosphatase. Which of the following would most likely be observed in an individual with Von Gierke disease? A. Increased glycogen in the liver B. Decreased post-meal glycolysis C. Decreased glucose tolerance D. Increased gluconeogenesis
Increased glycogen in the liver Glucose-6-phosphatase hydrolyzes glucose-6-phosphate into a phosphate molecule plus glucose, which can then be used by cells to generate energy. Without this enzyme, gluconeogenesis cannot be completed. Glycolysis would not be affected, and glucose tolerance would be expected to be normal. Glycogenolysis produces glucose-6-phosphate from glycogen stores in the body during times of fasting, or when blood glucose is low. However, without glucose-6-phosphatase, glucose cannot be made from glucose-6-phosphate. Therefore, the breakdown of glycogen is impaired in these individuals. Increase glycogen in the liver would be expected in an individual with Von Gierke disease.
_______ types of cells gravitate toward inflammation
Leukocytes
what cells make testosterone?
Leydig cells
Which amino acid can form a bond similar to a peptide bond
Lysine (form isopeptide bonds by reacting with carboxylic acid groups)
If an organism is similar in sequence to another and hybridizes to the same tissues, are they related?
Probably
What happens if you insert an exotoxin into the the inner membrane of the mitochondria?
Proton gradient across the mitochondria inner membrane will dissipate
Types of reactions
SN1: rate based on substrate, polar protic, ↑ hindrance, racemic SN2: rate based on substrate & nuc, polar aprotic, ↓ hindrance, inverted & optically active Nuc acyl subst: Ammonia/Amine --> Amide, Alcohol -> ester, Carbox acid -> Anhydride Dehydration (heat): Form double bond & remove H2O Hydrolysis: Proteolytic Cleavage
what is the purpose of glycoproteins or glycolipids?
communication AKA makes cells recognize each other
Heterozygote advantage
tendency for carrier of dangerous condition to have survival advantage
self-fulfilling prophecy
tendency for people to behave as they are expected to behave
self-verification
tendency to seek evidence to confirm the self-concept
Urethra
tube that carries urine from the bladder to the outside of the body + in males: where semen travels to the outside of the body
if you have twice the amount of voltage you need a
twice the amount of voltage drop
